UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-CSR

CERTIFIED SHAREHOLDER REPORT OF REGISTERED MANAGEMENT

INVESTMENT COMPANIES

Investment Company Act File Number 811-06351

Green Century Funds

114 State Street

Suite 200

Boston, MA 02109

(Address of principal executive offices)

Green Century Capital Management, Inc.

114 State Street

Suite 200

Boston, MA 02109

(Name and address of agent for service)

Registrant’s telephone number, including area code: (617) 482-0800

Date of fiscal year end: July 31

Date of reporting period: January 31, 2010

Item 1. Reports to Stockholders

The following is a copy of the report transmitted to shareholders pursuant to Rule 30e-1 under the Investment Company Act of 1940 (17 CFR 270.30e-1).

	SEMI-ANNUAL REPORT Green Century Balanced Fund Green Century Equity Fund January 31, 2010
An investment for your future.®	114 State Street, Boston, Massachusetts 02109

For information on the Green Century Funds^®, call 1-800-93-GREEN. For information on how to open an account and account services, call 1-800-221-5519 8:00 am to 6:00 pm Eastern Time, Monday through Friday. For share price and account information, call 1-800-221-5519, twenty-four hours a day.

Dear Green Century Funds Shareholder:

Many mainstream Wall Street investment firms solely focus on a profitable bottom line for themselves; independent, triple bottom line firms like Green Century Capital Management (Green Century) focus on what our investors care about: building a sustainable economy while seeking competitive financial returns.

Green Century forges a new path in the financial sector to provide investors a means to use the power of their investment dollars to encourage environmentally responsible corporate behavior, since business as usual will not create the green future we seek. Here are some of the ways Green Century is different from the mainstream Wall Street firms:

• Green Century was founded in 1991 by a partnership of non-profit environmental advocacy organizations. Our firm remains 100% owned by these groups and any profits generated on the fees we earn for managing the Green Century Funds belong to our non-profit founders. Instead of being constantly pressured to reach quarterly earnings targets, we have a long-term focus on staying true to our green mission. Bailouts are the closest Wall Street firms can claim to being non-profits.

• We are a small, nimble firm that has the freedom to invest in environmentally sound companies. The Green Century Funds do not invest in companies in every sector as many other mutual funds do. In fact, the Green Century Balanced Fund does not invest in any fossil fuel production or manufacturing companies because we support the transition to a less carbon intensive economy.

• A critical component of our green investing strategy is being an active shareholder and encouraging companies to be responsible corporate citizens. Unlike many large mutual fund companies, we do not always agree with management’s decisions. As investors, we have the right and the responsibility to hold companies accountable for their environmental performance. Environmentally-destructive practices and policies are not just bad for the planet—they can also create significant risks and disadvantages for companies.

Shareholder Advocacy Update As of this spring, Green Century is on track to have a record-setting year for our shareholder advocacy program. We have filed over 20 shareholder resolutions asking companies to take action on a range of critical environmental issues including disclosing the impacts of Canadian tar sands oil extraction, adopting sustainable seafood procurement policies and practices, reducing the amount of water used by electric utilities, and increasing transparency around corporate political spending.

This year Green Century launched a new high-profile shareholder campaign that encourages increased transparency and reducing the environmental risks associated with fossil fuel development. The new campaign seeks to ensure that development of natural gas is done in a way that does not have unintended and harmful consequences for the environment and human health. The shareholder proposals ask companies to increase transparency regarding the environmental impact of their operations and encourage companies to mitigate risks by switching to less toxic fracturing fluids and adopting best practices for drilling and managing wastes.

Green Century is committed to fostering a more sustainable economy through our robust advocacy efforts. We thank you for your continued investment in the Green Century Funds as we all work toward a healthier, more sustainable world.

If you have any questions, please do not hesitate to contact us at 1-800-93-GREEN or visit us on-line at: www.GreenCentury.com.

Respectfully,

Green Century Capital Management

THE GREEN CENTURY BALANCED FUND

The Green Century Balanced Fund seeks capital growth and income from a diversified portfolio of stocks and bonds that meet Green Century’s standards for corporate environmental performance. The portfolio managers of the Balanced Fund aim to invest in companies that are in the business of solving environmental problems or that are committed to reducing their environmental impact.

	AVERAGE ANNUAL RETURN* Total expense ratio: 1.38%	Six Months	One Year	Five Years	Ten Years
December 31, 2009	Green Century Balanced Fund	14.20%	22.44%	0.64%	0.53%
	Lipper Balanced Fund Index2	16.42%	23.35%	2.63%	2.79%
January 31, 2010	Green Century Balanced Fund	5.41%	23.63%	0.91%	-0.54%
	Lipper Balanced Fund Index2	7.95%	27.13%	2.55%	2.88%

* The performance data quoted represents past performance and is not a guarantee of future results. Investment return and principal value of an investment will fluctuate so that an investor’s shares, when redeemed, may be worth more or less than their original cost. Current performance may be lower or higher than the performance information quoted. To obtain performance information as of the most recent month-end, call 1-800-93-GREEN. Performance includes the reinvestment of income dividends and capital gain distributions. Performance shown does not reflect the deduction of taxes that a shareholder might pay on Fund distributions or the redemption of Fund shares.

During the six month periods ended December 31, 2009 and January 31, 2010, the Balanced Fund performance lagged the Lipper Balanced Fund Index, though both the Fund and that Index were up significantly. For the six months ended January 31, 2010, the Fund returned 5.41%, while the Lipper Balanced Fund Index returned 7.95%.

As the economy stabilized, stocks in the industrial, technology, and consumer discretionary sectors did particularly well. While the Balanced Fund does not hold any fossil-fuel energy company stocks, the Fund’s holdings of smaller companies’ stocks in solar and wind energy lagged the market in concert with oil and gas stocks. The Balanced Fund’s bond holdings participated in the overall recovery, with the prices of intermediate maturity corporate bonds increasing as the prospects for economic recovery strengthened.

The Fund’s equity holdings which positively contributed to its performance during the six months ended January 31, 2010 included: Cree¹, General Mills¹, Apple¹, and J.M. Smucker Co.¹, while poor performers included Advance Auto Parts¹, Sims Metal Management¹, First Solar¹, and Owens-Illinois¹.

The Balanced Fund’s portfolio managers believe the Fund is positioned to benefit from the moderate economic growth expected in

GREEN CENTURY BALANCED FUND

INVESTMENTS BY INDUSTRY

2

2010. The Fund’s equity holdings are weighted toward steady growth companies with higher domestic sales exposure and the Fund’s bond holdings are weighted toward short to intermediate maturity and high quality bonds.

The Green Century Balanced Fund invests in the stocks and bonds of environmentally responsible corporations of various sizes, including small, medium, and large companies. The value of the stocks held in the Balanced Fund will fluctuate in response to factors that may affect a single issuer, industry, or sector of the economy or may affect the market as a whole. Bonds are subject to a variety of risks including interest rate, credit, and inflation risk.

THE GREEN CENTURY EQUITY FUND

The Green Century Equity Fund invests essentially all of its assets in the stocks which make up the FTSE KLD 400 Social Index (the “Index”), comprised of 400 primarily large capitalization U.S. companies selected based on a comprehensive range of social and environmental sustainability criteria. The Equity Fund seeks to provide shareholders with a long-term total return that matches that of the Index.

	AVERAGE ANNUAL RETURN* Total expense ratio: 0.95%	Six Months	One Year	Five Years	Ten Years
December 31, 2009	Green Century Equity Fund	24.11%	30.37%	–0.33%	–2.45%
	S&P 500® Index3	22.59%	26.46%	0.42%	–0.95%
January 31, 2010	Green Century Equity Fund	10.56%	37.29%	–0.43%	–2.25%
	S&P 500® Index3	9.87%	33.14%	0.18%	–0.80%

* The performance data quoted represents past performance and is not a guarantee of future results. Investment return and principal value of an investment will fluctuate so that an investor’s shares, when redeemed, may be worth more or less than their original cost. Current performance may be lower or higher than the performance information quoted. To obtain performance information as of the most recent month-end, call 1-800-93-GREEN. Performance includes the reinvestment of income dividends and capital gain distributions. Performance shown does not reflect the deduction of taxes that a shareholder might pay on Fund distributions or the redemption of Fund shares.

The Green Century Equity Fund outperformed the S&P 500^® Index for the six-month and one year periods ended December 31, 2009 and January 31, 2010. For the six month period ended January 31, 2010, the Equity Fund’s return was 10.56%, while the S&P 500^® Index was up 9.87%.

The U.S. economy returned to positive growth in the third quarter of 2009 and expanded again during the fourth quarter. The Federal Reserve kept interest rates at historically low levels in an ongoing attempt to stimulate growth. Economic data releases were mixed for the six months ended January 31, 2010, with improvements in some indicators such as manufacturing indices but ongoing high unemployment and relatively low consumer confidence. The U.S. stock market rose during the period led by improvements in the financial and consumer discretionary sectors.

3

The performance of the Equity Fund was helped, relative to the S&P 500^®, in part due to an underweight in energy, diversified financials, electric utilities and diversified telecommunications. The Equity Fund did not own companies such as MEMC Electronic Materials¹, Iron Mountain¹, and Owens-Illinois¹ which were down significantly for the six months ended January 31, 2010. The fund benefited from being overweight to software and commercial banks during the period due predominantly to owning Microsoft¹ and Wells Fargo¹, respectively.

Conversely, the Equity Fund was overweight in communications equipment stocks which were among the worst performers on a relative basis. Qualcomm¹ and Cisco Systems¹ performed poorly as companies continued with cost-cutting strategies and delayed spending in response to the recession. The Fund was also hurt by being underweighted in aerospace and defense and not owning companies such as Boeing¹ and United Technologies¹. These companies performed better than the overall market during the period as the government announced increased defense spending over the next few years.

The Equity Fund, like other mutual funds invested primarily in stocks, carries the risk of investing in the stock market. The large companies in which the Equity Fund is invested may perform worse than the stocks market as a whole. The Equity Fund will not shift concentration from one industry to another or from stocks to bonds or cash, in order to defend against a falling stock market.

GREEN CENTURY EQUITY FUND

INVESTMENTS BY INDUSTRY

4

The Green Century Funds’ proxy voting guidelines and a record of the Funds’ proxy votes for the year ended June 30, 2009 are available without charge, upon request, (i) at www.greencentury.com, (ii) by calling 1-800-93-GREEN, (iii) sending an e-mail to info@greencentury.com, and (iv) on the Securities and Exchange Commission’s website at www.sec.gov.

The Green Century Funds file their complete schedule of portfolio holdings with the SEC for the first and third quarters of the year on Form N-Q. The Green Century Funds’ Forms N-Q are available on the EDGAR database on the SEC’s website at www.sec.gov. These Forms may also be reviewed and copied at the SEC’s Public Reference Room in Washington D.C. Information about the operation of the Public Reference Room may be obtained by calling 1-800-SEC-0330. The information on Form N-Q may also be obtained by calling 1-800-93-GREEN, or by e-mailing a request to info@greencentury.com.

¹ As of January 31, 2010, the following companies comprised the listed percentages of each of the Green Century Funds:

Portfolio Holding	GREEN CENTURY BALANCED FUND	GREEN CENTURY EQUITY FUND
Cree	1.33%	0.12%
General Mills	2.39%	0.46%
Apple	1.43%	0.00%
J.M. Smucker Co.	1.56%	0.14%
Advance Auto Parts	0.63%	0.00%
Sims Metal Management	0.57%	0.00%
First Solar	0.45%	0.14%
Owens-Illinois	0.39%	0.00%
MEMC Electronic Materials	0.00%	0.00%
Iron Mountain	0.00%	0.00%
Microsoft	1.23%	5.02%
Wells Fargo	0.00%	2.90%
Qualcomm	0.00%	1.30%
Cisco Systems	0.84%	2.60%
Boeing	0.00%	0.00%
United Technologies	0.00%	0.00%

Portfolio composition will change due to ongoing management of the Funds. Please refer to the Green Century Funds website for current information regarding the Funds’ portfolio holdings. These holdings are subject to risk as described in the Funds’ prospectus. References to specific investments should not be construed as a recommendation of the securities by the Funds, their administrator, or their distributor.

² Lipper Analytical Services, Inc. (“Lipper”) is a respected mutual fund reporting service. The Lipper Balanced Fund Index includes the 30 largest funds whose primary objective is to conserve principal by maintaining at all times a balanced portfolio of both stocks and bonds. Typically the stock/bond ratio ranges around 60%/40%.

³ The S&P 500^® Index is an unmanaged index of 500 selected common stocks, most of which are listed on the New York Stock Exchange. The S&P 500^® Index is heavily weighted toward stocks with large market capitalization and represents approximately two-thirds of the total market value of all domestic stocks. It is not possible to invest directly in the S&P 500^® Index.

This material must be preceded or accompanied by a current prospectus.

Distributor: UMB Distribution Services, LLC, 3/10

5

GREEN CENTURY FUNDS EXPENSE EXAMPLE

For the six months ended January 31, 2010

As a shareholder of the Green Century Funds (the “Funds”), you incur two types of costs: (1) transaction costs, including redemption fees on certain redemptions; and (2) ongoing costs, including management fees and other Fund expenses. This example is intended to help you understand your ongoing costs (in dollars) of investing in the Funds and to compare these costs with the ongoing costs of investing in other mutual funds.

The example is based on an investment of $1,000 invested at the beginning of the period and held for the entire period from August 1, 2009 to January 31, 2010 (the “period”).

Actual Expenses.    The first line of the table below provides information about actual account values and actual expenses. You may use the information in this line, together with the amount you invested, to estimate the expenses you paid over the period. Simply divide your account value by $1,000 (for example, an $8,600 account value divided by $1,000 equals 8.6), then multiply the result by the number in the first line under the heading entitled “Expenses Paid During the Period” to estimate the expenses you paid on your account during the period.

Hypothetical Example for Comparison Purposes.    The second line of the table below provides information about hypothetical account values and hypothetical expenses based on the Funds’ actual expense ratios and an assumed rate of return of 5% per year before expenses, which is not the actual return of either of the Funds. The hypothetical account values and expenses may not be used to estimate the actual ending account balance or expenses you paid for the period. You may use this information to compare the ongoing costs of investing in the Funds and other funds. To do so, compare this 5% hypothetical example with the 5% hypothetical examples that appear in the shareholder reports of other funds.

Please note that the expenses shown in the table are meant to highlight your ongoing costs only and do not reflect any transactional costs, such as redemption fees on shares held for 60 days or less. Therefore, the second line of the table is useful in comparing the ongoing costs only, and will not help you determine the relative total costs of owning different funds. In addition, if these transactional costs were included, your costs could have been higher.

	BEGINNING ACCOUNT VALUE AUGUST 1, 2009		ENDING ACCOUNT VALUE JANUARY 31, 2010		EXPENSES PAID DURING THE PERIOD1
Balanced Fund
Actual Expenses	$	1,000.00	$	1,054.10	$	7.15
Hypothetical Example, assuming a 5% return before expenses		1,000.00		1,018.04		7.02
Equity Fund
Actual Expenses		1,000.00		1,105.60		5.04
Hypothetical Example, assuming a 5% return before expenses		1,000.00		1,020.21		4.84

¹ Expenses are equal to the Funds’ annualized expense ratios (1.38% for the Balanced Fund and .95% for the Equity Fund), multiplied by the average account value over the period, multiplied by 184/365 (to reflect the one-half year period).

6

GREEN CENTURY BALANCED FUND PORTFOLIO OF INVESTMENTS

January 31, 2010

(unaudited)

COMMON STOCKS — 64.1%
	SHARES	VALUE
Technology Hardware & Equipment — 7.6%
Apple, Inc. (a)	3,761	$	722,563
Cisco Systems, Inc. (a)	18,940		425,582
EMC Corporation (a)	15,000		250,050
Hewlett-Packard Company	19,000		894,330
International Business Machines Corporation	10,700		1,309,573
NETGEAR, Inc. (a)	11,362		234,512
			3,836,610
Capital Goods — 6.9%
3M Company	10,795		868,890
ABB Ltd. American Depositary Receipt (a)(b)	8,940		161,188
Emerson Electric Company	8,844		367,380
Gardner Denver, Inc.	8,400		334,740
Illinois Tool Works, Inc.	11,990		522,644
Koninklijke Philips Electronics N.V. American Depositary Receipt (b)	5,650		170,856
Middleby Corporation (a)	3,000		135,180
Pentair, Inc.	8,917		272,325
Quanta Services, Inc. (a)	9,600		174,912
W.W. Grainger, Inc.	4,900		486,472
			3,494,587
Renewable Energy & Energy Efficiency — 5.6%
American Superconductor Corporation (a)	4,500		171,090
Ballard Power Systems, Inc. (a)	70,958		158,946
Cree, Inc. (a)	12,000		670,920
First Solar, Inc. (a)	2,015		228,299
GT Solar International, Inc. (a)	18,000		103,500
International Rectifier Corporation (a)	21,000		378,840
Itron, Inc. (a)	3,720		228,929
Johnson Controls, Inc.	5,957		165,783
OM Group, Inc. (a)	8,600		280,532
Ormat Technologies, Inc.	7,800		268,476
Suntech Power Holdings Company Ltd. American Depository Receipt (a)(b)	11,947		161,404
			2,816,719

	SHARES	VALUE
Pharmaceuticals & Biotechnology — 5.0%
Amgen, Inc. (a)	6,317	$	369,418
GlaxoSmithKline plc American Depositary Receipt (b)	9,578		373,638
Johnson & Johnson	13,640		857,410
Teva Pharmaceutical Industries Ltd. American Depositary Receipt (b)	11,485		651,429
Waters Corporation (a)	5,000		284,900
			2,536,795
Diversified Financials — 4.8%
American Express Company	5,755		216,733
Bank of America Corporation	31,870		483,787
Charles Schwab Corporation (The)	16,000		292,640
Goldman Sachs Group, Inc. (The)	3,300		490,776
JPMorgan Chase & Company	18,177		707,812
Stifel Financial Corporation (a)	4,700		245,810
			2,437,558
Food & Beverage — 4.3%
Diamond Foods, Inc.	5,121		183,946
General Mills, Inc.	16,900		1,205,139
J. M. Smucker Company (The)	13,105		787,218
			2,176,303
Insurance — 4.0%
Aflac, Inc.	4,500		217,935
Chubb Corporation	11,345		567,250
HCC Insurance Holdings, Inc.	14,000		379,400
Horace Mann Educators Corporation	17,000		203,830
Progressive Corporation (The)	23,500		389,630
W. R. Berkley Corporation	10,300		250,599
			2,008,644
Healthcare Equipment & Services — 3.9%
Baxter International, Inc.	8,600		495,274
Becton, Dickinson and Company	3,300		248,721
Gen-Probe, Inc. (a)	4,998		214,564
Hologic, Inc. (a)	14,950		225,297
Medtronic, Inc.	12,250		525,402
UnitedHealth Group, Inc.	7,530		248,490
			1,957,748
Software & Services — 3.6%
Google, Inc., Class A (a)	907		480,184
Microsoft Corporation	21,950		618,551

7

GREEN CENTURY BALANCED FUND PORTFOLIO OF INVESTMENTS January 31, 2010 (unaudited) continued

	SHARES	VALUE
Software & Services — (continued)
Oracle Corporation	30,798	$	710,202
			1,808,937
Materials — 2.8%
Air Products & Chemicals, Inc.	4,300		326,628
Ecolab, Inc.	14,043		616,488
Owens-Illinois, Inc. (a)	7,200		195,984
Sims Metal Management Ltd. American Depositary Receipt (b)	15,200		285,760
			1,424,860
Telecommunication Services — 2.8%
AT&T, Inc.	30,475		772,846
Telefonica S.A. American Depositary Receipt (b)	8,562		613,039
			1,385,885
Food & Staples Retailing — 2.3%
Costco Wholesale Corporation	10,840		622,541
Sysco Corporation	18,635		521,594
			1,144,135
Media — 1.8%
John Wiley & Sons, Inc., Class A	14,225		593,894
McGraw-Hill Companies, Inc. (The)	8,969		317,951
			911,845
Semiconductors — 1.5%
Intel Corporation	38,330		743,602
Consumer Durables & Apparel — 1.4%
Deckers Outdoor Corporation (a)	2,012		197,518
Jarden Corporation	9,854		300,350
Timberland Company (The), Class A (a)	11,000		189,200
			687,068
Consumer Services — 1.3%
Chipotle Mexican Grill, Inc. (a)	2,083		200,926
Panera Bread Company, Class A (a)	2,556		182,550
Starbucks Corporation (a)	11,147		242,893
			626,369
Transportation — 1.2%
Canadian Pacific Railway Ltd.	4,000		188,000
Expeditors International of Washington, Inc.	2,578		87,910

	SHARES		VALUE
Transportation — (continued)
United Parcel Service, Inc., Class B		6,064	$	350,317
				626,227
Household & Personal Products — 1.2%
Church & Dwight Company, Inc.		9,875		595,364
Retailing — 0.6%
Advance Auto Parts, Inc.		8,100		319,545
Automobiles & Components — 0.6%
Toyota Motor Corporation American Depositary Receipt (b)		4,083		314,391
Healthy Living — 0.4%
United Natural Foods, Inc. (a)		8,000		216,880
Banks — 0.3%
Royal Bank of Canada		3,236		158,758
Commercial & Professional Services — 0.2%
Interface, Inc., Class A		11,600		94,076
Total Common Stocks (Cost $29,943,967)				32,322,906
CORPORATE BONDS & NOTES — 23.1%
	PRINCIPAL AMOUNT		VALUE
Telecommunication Services — 5.4%
AT&T Corporation
7.30%, due 11/15/11 (c)	$	1,000,000		1,106,060
BellSouth Corporation
4.75%, due 11/15/12		500,000		536,117
France Telecom S.A.
7.75%, due 3/1/11 (b)(c)		500,000		535,999
Verizon Communications, Inc.
5.25%, due 4/15/13		500,000		546,953
				2,725,129
Diversified Financials — 5.3%
Goldman Sachs Group, Inc. (The)
6.60%, due 1/15/12		500,000		545,202
JPMorgan Chase & Company
4.60%, due 1/17/11		500,000		517,791
JPMorgan Chase & Company
4.50%, due 1/15/12		500,000		525,285

8

GREEN CENTURY BALANCED FUND PORTFOLIO OF INVESTMENTS January 31, 2010 (unaudited) continued

	PRINCIPAL AMOUNT		VALUE
Diversified Financials — (continued)
SLM Corporation
4.00%, due 7/25/14 (d)	$	1,235,000	$	1,060,828
				2,649,106
Pharmaceuticals & Biotechnology — 3.3%
Abbott Laboratories
5.60%, due 11/30/17		500,000		554,937
Amgen, Inc.
4.85%, due 11/18/14		500,000		543,188
Wyeth
5.50%, due 3/15/13 (c)		500,000		552,339
				1,650,464
Technology Hardware & Equipment — 2.0%
Xerox Corporation
7.625%, due 6/15/13		1,000,000		1,023,637
Healthcare Equipment & Services — 1.8%
Aetna, Inc.
5.75%, due 6/15/11		595,000		626,964
UnitedHealth Group, Inc.
4.875%, due 4/1/13		250,000		268,087
				895,051
Renewable Energy & Energy Efficiency — 1.0%
Johnson Controls, Inc.
5.50%, due 1/15/16		500,000		522,272
Software & Services — 1.0%
Oracle Corporation
5.00%, due 1/15/11		500,000		519,018
Real Estate — 1.0%
Simon Property Group LP
4.875%, due 8/15/10		500,000		509,318
Automobiles & Components — 1.0%
Toyota Motor Credit Corporation
5.50%, due 7/25/17 (b)(c)		500,000		506,537
Transportation — 1.0%
Ryder System, Inc.
4.625%, due 4/1/10		500,000		501,368

	PRINCIPAL AMOUNT		VALUE
Consumer Durables & Apparel — 0.3%
Newell Rubbermaid, Inc.
4.00%, due 5/1/10	$	141,000	$	141,813
Total Corporate Bonds & Notes (Cost $11,343,392)				11,643,713
U.S. GOVERNMENT AGENCIES — 9.4%
Fannie Mae Pool
5.50%, due 3/1/12		68,935		71,049
Federal Farm Credit Bank
4.50%, due 10/25/11		500,000		530,830
Federal Farm Credit Bank
3.40%, due 4/22/16		500,000		496,331
Federal Home Loan Bank
3.125%, due 12/13/13		550,000		568,082
Federal Home Loan Bank
5.625%, due 6/13/16		1,000,000		1,048,854
Federal Home Loan Bank
3.875%, due 12/14/18		550,000		553,702
Federal Home Loan Mortgage Corporation
2.00%, due 11/15/14 (c)		500,000		507,225
Federal Home Loan Mortgage Corporation
3.75%, due 3/27/19		500,000		496,955
Federal National Mortgage Association
3.00%, due 4/15/15		500,000		501,007
Total U.S. Government Agencies (Cost $4,695,590)				4,774,035
CERTIFICATES OF DEPOSIT — 0.4%
Self Help Credit Union Environmental Certificate of Deposit
3.40%, due 8/8/10		95,000		95,025
Shorebank Pacific Time Deposit Receipt
3.75%, due 8/8/11		95,000		95,000
Total Certificates Of Deposit (Cost $190,025)				190,025

9

GREEN CENTURY BALANCED FUND PORTFOLIO OF INVESTMENTS January 31, 2010 (unaudited) concluded

SHORT-TERM OBLIGATION — 2.8%
		VALUE
Repurchase Agreement— State Street Bank & Trust Repurchase Agreement, 0.01%, dated 01/29/10, due 02/01/10, proceeds $1,416,204 (collateralized by Federal Home Loan Bank, 4.375%, due 09/17/2010, value $1,447,546) (Cost $1,416,203)	$	1,416,203
TOTAL INVESTMENTS (e) — 99.8%
(Cost $47,589,177)		50,346,882
Other Assets Less Liabilities — 0.2%		87,636
NET ASSETS — 100.0%	$	50,434,518

(a) Non-income producing security.

(b) Securities whose values are determined or significantly influenced by trading in markets other than the United States or Canada.

(c) Step rate bond. Rate shown is currently in effect at January 31, 2010.

(d) Floating rate bond. Rate shown is currently in effect at January 31, 2010.

(e) The cost of investments for federal income tax purposes is $47,592,431 resulting in gross unrealized appreciation and depreciation of $5,264,304 and $2,509,853 respectively, or net unrealized appreciation of $2,754,451.

See Notes to Financial Statements

10

GREEN CENTURY EQUITY FUND PORTFOLIO OF INVESTMENTS

January 31, 2010

(unaudited)

COMMON STOCKS — 99.7%
	SHARES	VALUE
Technology Hardware & Equipment — 12.0%
3Com Corporation (a)	3,600	$	26,820
Adaptec, Inc. (a)	800		2,432
ADC Telecommunications, Inc. (a)	1,000		5,310
Arrow Electronics, Inc. (a)	1,050		27,583
Cisco Systems, Inc. (a)	53,257		1,196,685
Corning, Inc.	14,358		259,593
Dell, Inc. (a)	18,095		233,425
Echelon Corporation (a)	282		2,394
EMC Corporation (a)	18,969		316,213
Hewlett-Packard Company	21,937		1,032,575
Imation Corporation (a)	300		2,682
International Business Machines Corporation	12,151		1,487,161
Lexmark International, Inc. (a)	700		18,053
Molex, Inc.	733		14,777
NetApp, Inc. (a)	3,137		91,381
Palm, Inc. (a)	1,576		16,375
Plantronics, Inc.	400		10,568
Polycom, Inc. (a)	800		17,944
QUALCOMM, Inc.	15,274		598,588
Seagate Technology	4,740		79,300
Tellabs, Inc. (a)	4,074		26,196
Xerox Corporation	8,368		72,969
			5,539,024
Software & Services — 10.5%
Adobe Systems, Inc. (a)	4,795		154,878
Advent Software, Inc. (a)	294		11,099
Autodesk, Inc. (a)	2,050		48,769
Automatic Data Processing, Inc.	4,592		187,308
BMC Software, Inc. (a)	1,700		65,688
Compuware Corporation (a)	2,208		16,759
Convergys Corporation (a)	1,100		11,770
eBay, Inc. (a)	11,860		273,017
Electronic Arts, Inc. (a)	3,008		48,970
Factset Research Systems, Inc.	344		21,672
Google, Inc., Class A (a)	2,168		1,147,783
Microsoft Corporation	82,101		2,313,606
Novell, Inc. (a)	3,000		13,410
Paychex, Inc.	3,391		98,305
Red Hat, Inc. (a)	1,340		36,475
Salesforce.com, Inc. (a)	857		54,462
Symantec Corporation (a)	7,489		126,939
Yahoo!, Inc. (a)	12,799		192,113
			4,823,023

	SHARES	VALUE
Pharmaceuticals & Biotechnology — 9.9%
Affymetrix, Inc. (a)	500	$	2,640
Allergan, Inc.	2,877		165,427
Amgen, Inc. (a)	9,437		551,876
Amylin Pharmaceuticals, Inc. (a)	1,421		25,550
Biogen Idec, Inc. (a)	2,712		145,743
Cubist Pharmaceuticals, Inc. (a)	439		8,995
Dionex Corporation (a)	150		10,477
Endo Pharmaceuticals Holdings, Inc. (a)	1,020		20,512
Genzyme Corporation (a)	2,452		133,045
Gilead Sciences, Inc. (a)	8,315		401,365
Illumina, Inc. (a)	1,124		41,239
Johnson & Johnson	25,623		1,610,662
Life Technologies Corporation (a)	1,632		81,127
Merck & Company, Inc.	28,020		1,069,804
Millipore Corporation (a)	500		34,485
Techne Corporation	350		22,967
Thermo Fisher Scientific, Inc. (a)	3,771		174,032
Waters Corporation (a)	900		51,282
			4,551,228
Banks — 6.2%
Bank of Hawaii Corporation	431		19,602
BB&T Corporation	6,429		179,176
Cathay General Bancorp	400		3,832
Comerica, Inc.	1,362		47,003
Fifth Third Bancorp	7,066		87,901
First Horizon National Corporation (a)	1,998		25,874
Heartland Financial USA, Inc.	100		1,395
Hudson City Bancorp, Inc.	4,912		65,182
Keycorp	8,118		58,287
M&T Bank Corporation	1,095		80,756
NewAlliance Bancshares, Inc.	1,000		11,640
People’s United Financial, Inc.	2,960		47,863
PNC Financial Services Group, Inc.	4,217		233,748
Popular, Inc.	6,963		14,970
Regions Financial Corporation	11,430		72,581
SunTrust Banks, Inc.	4,502		109,534
Synovus Financial Corporation	4,580		12,641
U.S. Bancorp	17,533		439,728
Umpqua Holdings Corporation	988		12,212
Wells Fargo & Company	47,007		1,336,409
			2,860,334

11

GREEN CENTURY EQUITY FUND PORTFOLIO OF INVESTMENTS January 31, 2010 (unaudited) continued

	SHARES	VALUE
Retailing — 6.0%
Amazon.com, Inc. (a)	3,059	$	383,629
AutoZone, Inc. (a)	346		53,640
Bed Bath & Beyond, Inc. (a)	2,434		94,196
Best Buy Company, Inc.	3,894		142,715
Carmax, Inc. (a)	1,876		38,702
Charming Shoppes, Inc. (a)	800		4,648
Family Dollar Stores, Inc.	1,265		39,063
Foot Locker, Inc.	1,300		14,677
Gap, Inc. (The)	4,868		92,881
Genuine Parts Company	1,491		56,181
Home Depot, Inc.	15,502		434,211
J.C. Penney Company, Inc.	2,134		52,987
Kohl’s Corporation (a)	2,741		138,064
Limited Brands, Inc.	3,078		58,544
Lowe’s Companies, Inc.	13,514		292,578
Men’s Wearhouse, Inc. (The)	500		10,075
Netflix, Inc. (a)	526		32,744
Nordstrom, Inc.	2,057		71,049
Office Depot, Inc. (a)	2,500		14,200
Pep Boys — Manny, Moe & Jack (The)	300		2,505
RadioShack Corporation	1,200		23,424
Staples, Inc.	6,755		158,472
Target Corporation	6,970		357,352
Tiffany & Company	1,073		43,575
TJX Companies, Inc.	3,965		150,710
			2,760,822
Household & Personal Products — 5.6%
Alberto-Culver Company	992		28,163
Avon Products, Inc.	3,991		120,289
Church & Dwight Company, Inc.	634		38,224
Clorox Company	1,290		76,329
Colgate-Palmolive Company	4,584		366,858
Estee Lauder Companies, Inc. (The), Class A	1,099		57,719
Kimberly-Clark Corporation	3,837		227,879
Nu Skin Enterprises, Inc., Class A	500		11,620
Procter & Gamble Company	27,065		1,665,851
WD-40 Company	103		3,169
			2,596,101
Healthcare Equipment & Services — 5.6%
Baxter International, Inc.	5,583		321,525
Beckman Coulter, Inc.	636		41,575

	SHARES	VALUE
Healthcare Equipment & Services — (continued)
Becton, Dickinson and Company	2,165	$	163,176
Cerner Corporation (a)	770		58,251
CIGNA Corporation	2,533		85,539
Cross Country Healthcare, Inc. (a)	200		1,812
Edwards Lifesciences Corporation (a)	500		44,810
Gen-Probe, Inc. (a)	491		21,079
Health Management Associates, Inc., Class A (a)	2,200		14,608
Henry Schein, Inc. (a)	880		47,564
Hill-Rom Holdings, Inc.	600		14,022
Hospira, Inc. (a)	1,509		76,416
Humana, Inc. (a)	1,493		72,590
Idexx Laboratories, Inc. (a)	538		28,240
IMS Health, Inc.	1,600		34,624
Intuitive Surgical, Inc. (a)	354		116,133
Invacare Corporation	300		7,512
McKesson Corporation	2,434		143,168
Medtronic, Inc.	10,227		438,636
Molina Healthcare, Inc. (a)	100		2,225
Patterson Companies, Inc. (a)	1,155		32,987
Quest Diagnostics, Inc.	1,690		94,082
St. Jude Medical, Inc. (a)	3,088		116,510
Stryker Corporation	2,779		144,286
Varian Medical Systems, Inc. (a)	1,205		60,599
WellPoint, Inc. (a)	4,235		269,854
Zimmer Holdings, Inc. (a)	2,007		113,034
			2,564,857
Energy — 5.3%
Apache Corporation	3,069		303,125
Cameron International Corporation (a)	2,205		83,040
Chesapeake Energy Corporation	6,000		148,680
Clean Energy Fuels Corporation (a)	200		3,348
Devon Energy Corporation	4,105		274,665
Diamond Offshore Drilling, Inc.	655		59,952
EOG Resources, Inc.	2,328		210,498
Helmerich & Payne, Inc.	953		39,864
Hess Corporation	2,997		173,197
National Oilwell Varco, Inc.	3,906		159,755
Newfield Exploration Company (a)	1,226		60,000
Noble Energy, Inc.	1,620		119,783
Pioneer Natural Resources Company	1,100		48,378

12

GREEN CENTURY EQUITY FUND PORTFOLIO OF INVESTMENTS January 31, 2010 (unaudited) continued

	SHARES	VALUE
Energy — (continued)
Quicksilver Resources, Inc. (a)	609	$	8,094
Smith International, Inc.	2,376		72,040
Southwestern Energy Company (a)	3,210		137,645
Spectra Energy Corporation	6,024		128,010
Ultra Petroleum Corporation (a)	1,339		61,514
Williams Companies, Inc.	5,375		112,015
XTO Energy, Inc.	5,356		238,717
			2,442,320
Food & Beverage — 4.5%
Campbell Soup Company	2,374		78,603
Darling International, Inc. (a)	552		4,300
Dean Foods Company (a)	1,664		29,336
Flowers Foods, Inc.	953		23,148
General Mills, Inc.	2,972		211,933
Green Mountain Coffee Roasters, Inc. (a)	385		32,656
H.J. Heinz Company	2,951		128,752
Hershey Company (The)	1,446		52,678
J. M. Smucker Company (The)	1,039		62,413
Kellogg Company	2,655		144,485
Kraft Foods, Inc., Class A	13,647		377,476
McCormick & Company, Inc.	1,150		41,745
PepsiCo, Inc.	14,388		857,813
Tootsie Roll Industries, Inc.	218		5,675
			2,051,013
Capital Goods — 4.4%
3M Company	6,525		525,197
A.O. Smith Corporation	252		10,730
AMETEK, Inc.	1,067		38,881
Apogee Enterprises, Inc.	300		4,128
Baldor Electric Company	400		9,872
Brady Corporation, Class A	450		12,717
CLARCOR, Inc.	450		14,571
Cooper Industries Ltd., Class A	1,552		66,581
Cummins, Inc.	1,794		81,017
Deere & Company	3,832		191,408
Donaldson Company, Inc.	712		27,227
EMCOR Group, Inc. (a)	600		14,436
Emerson Electric Company	6,976		289,783
Fastenal Company	1,426		59,151
Gardner Denver, Inc.	464		18,490
General Cable Corporation (a)	450		13,095
Graco, Inc.	554		14,786

	SHARES	VALUE
Capital Goods — (continued)
Granite Construction, Inc.	429	$	13,248
Hubbell, Inc., Class B	500		21,530
Illinois Tool Works, Inc.	4,529		197,419
Kadant, Inc. (a)	100		1,522
Lincoln Electric Holdings, Inc.	421		20,557
Masco Corporation	3,300		44,748
Nordson Corporation	263		14,870
Owens Corning (a)	991		25,498
Pall Corporation	1,050		36,194
Quanta Services, Inc. (a)	1,811		32,996
Rockwell Automation, Inc.	1,294		62,423
Simpson Manufacturing Company, Inc.	300		7,398
Spirit Aerosystems Holdings, Inc. (a)	900		19,305
SPX Corporation	490		26,676
Tennant Company	150		3,590
Thomas & Betts Corporation (a)	521		17,589
Timken Company	948		21,245
W.W. Grainger, Inc.	693		68,801
Westinghouse Air Brake Technologies Corporation	429		16,444
			2,044,123
Diversified Financials — 4.2%
American Express Company	10,901		410,532
Bank of New York Mellon Corporation (The)	11,054		321,561
BlackRock, Inc.	187		39,984
Capital One Financial Corporation	4,069		149,983
Charles Schwab Corporation (The)	10,551		192,978
CME Group, Inc.	618		177,255
Franklin Resources, Inc.	1,606		159,042
Medallion Financial Corporation	100		803
Northern Trust Corporation	2,265		114,428
NYSE Euronext	2,456		57,495
PHH Corporation (a)	500		8,720
State Street Corporation	4,521		193,860
T. Rowe Price Group, Inc.	2,398		118,989
TradeStation Group, Inc. (a)	200		1,414
			1,947,044
Semiconductors — 3.5%
Advanced Micro Devices, Inc. (a)	6,183		46,125
Analog Devices, Inc.	2,587		69,746

13

GREEN CENTURY EQUITY FUND PORTFOLIO OF INVESTMENTS January 31, 2010 (unaudited) continued

	SHARES	VALUE
Semiconductors — (continued)
Entegris, Inc. (a)	800	$	2,912
Intel Corporation	51,128		991,883
Lam Research Corporation (a)	1,075		35,486
LSI Corporation (a)	5,700		28,443
Micron Technology, Inc. (a)	8,041		70,118
National Semiconductor Corporation	2,219		29,424
Novellus Systems, Inc. (a)	900		18,810
Texas Instruments, Inc.	11,655		262,237
Xilinx, Inc.	2,423		57,134
			1,612,318
Transportation — 2.8%
AMR Corporation (a)	3,445		23,839
Arkansas Best Corporation	200		4,508
C.H. Robinson Worldwide, Inc.	1,517		85,908
Continental Airlines, Inc., Class B (a)	1,223		22,491
CSX Corporation	3,583		153,567
Expeditors International of Washington, Inc.	1,965		67,007
FedEx Corporation	2,875		225,256
Genesee & Wyoming, Inc., Class A (a)	330		9,725
J.B. Hunt Transport Services, Inc.	907		27,809
JetBlue Airways Corporation (a)	2,453		12,118
Kansas City Southern (a)	774		22,988
Norfolk Southern Corporation	3,354		157,839
Ryder System, Inc.	500		18,200
Southwest Airlines Company	6,912		78,313
United Parcel Service, Inc., Class B	6,511		376,140
			1,285,708
Food & Staples Retailing — 2.6%
Costco Wholesale Corporation	3,989		229,089
CVS Caremark Corporation	13,033		421,878
Safeway, Inc.	3,755		84,300
Sysco Corporation	5,386		150,754
Walgreen Company	9,144		329,641
			1,215,662
Materials — 2.5%
Air Products & Chemicals, Inc.	1,971		149,717
Airgas, Inc.	577		24,384
Alcoa, Inc.	9,096		115,792

	SHARES	VALUE
Materials — (continued)
Bemis Company, Inc.	892	$	25,030
Calgon Carbon Corporation (a)	400		5,356
Domtar Corporation (a)	408		19,817
Ecolab, Inc.	2,202		96,668
H.B. Fuller Company	400		8,008
Horsehead Holding Corporation (a)	313		3,067
Lubrizol Corporation	610		44,951
MeadWestvaco Corporation	1,550		37,308
Minerals Technologies, Inc.	150		7,170
Nalco Holding Company	1,300		30,654
Nucor Corporation	2,874		117,259
Praxair, Inc.	2,828		213,005
Rock-Tenn Company, Class A	291		12,423
Schnitzer Steel Industries, Inc., Class A	192		7,776
Sealed Air Corporation	1,400		27,776
Sigma-Aldrich Corporation	1,129		54,023
Sonoco Products Company	901		25,012
Valspar Corporation	900		23,832
Wausau Paper Corporation (a)	442		3,898
Weyerhaeuser Company	1,976		78,842
Worthington Industries, Inc.	889		12,864
			1,144,632
Insurance — 2.4%
Aflac, Inc.	4,269		206,748
Chubb Corporation	3,156		157,800
Cincinnati Financial Corporation	1,470		38,793
Erie Indemnity Company	429		16,731
Hartford Financial Services Group, Inc.	3,497		83,893
Lincoln National Corporation	2,787		68,504
Phoenix Companies, Inc. (The) (a)	1,000		2,350
Principal Financial Group, Inc.	2,781		64,102
Progressive Corporation (The)	6,353		105,333
StanCorp Financial Group, Inc.	420		18,052
Travelers Companies, Inc. (The)	5,048		255,782
Unum Group	3,115		60,961
Wesco Financial Corporation	10		3,530
			1,082,579
Telecommunication Services — 2.2%
Frontier Communications Corporation	2,900		22,069
Leap Wireless International, Inc. (a)	482		6,358
MetroPCS Communications, Inc. (a)	2,678		15,077

14

GREEN CENTURY EQUITY FUND PORTFOLIO OF INVESTMENTS January 31, 2010 (unaudited) continued

	SHARES	VALUE
Telecommunication Services — (continued)
Qwest Communications International, Inc.	15,161	$	63,828
Sprint Nextel Corporation (a)	27,633		90,636
Verizon Communications, Inc.	26,199		770,775
Windstream Corporation	3,762		38,786
			1,007,529
Consumer Services — 2.0%
Capella Education Company (a)	128		9,393
Choice Hotels International, Inc.	638		20,250
Darden Restaurants, Inc.	1,371		50,672
DeVry, Inc.	674		41,154
McDonald’s Corporation	9,972		622,552
Peet’s Coffee & Tea, Inc. (a)	122		3,989
Starbucks Corporation (a)	6,826		148,739
			896,749
Consumer Durables & Apparel — 1.6%
Black & Decker Corporation	543		35,110
Coach, Inc.	2,984		104,082
Deckers Outdoor Corporation (a)	100		9,817
Eastman Kodak Company (a)	2,434		14,726
Harman International Industries, Inc.	627		22,290
KB Home	941		14,378
Leggett & Platt, Inc.	1,400		25,564
Liz Claiborne, Inc. (a)	900		4,383
Mattel, Inc.	3,362		66,299
NIKE, Inc., Class B	2,696		171,870
Phillips-Van Heusen Corporation	500		19,645
Pulte Homes, Inc. (a)	3,535		37,188
Snap-On, Inc.	500		20,440
Stanley Works (The)	686		35,158
Timberland Company (The), Class A (a)	400		6,880
Tupperware Brands Corporation	600		25,476
Under Armour, Inc., Class A (a)	250		6,350
VF Corporation	1,031		74,263
Whirlpool Corporation	679		51,047
			744,966
Media — 1.6%
Discovery Communications, Inc., Class A (a)	1,203		35,681
John Wiley & Sons, Inc., Class A	436		18,203

	SHARES	VALUE
Media — (continued)
New York Times Company (The), Class A (a)	1,313	$	16,964
Omnicom Group, Inc.	2,898		102,299
Scholastic Corporation	200		5,980
Virgin Media, Inc.	3,157		44,798
Walt Disney Company (The)	17,152		506,842
Washington Post Company (The), Class B	25		10,865
			741,632
Utilities — 1.5%
AGL Resources, Inc.	700		24,703
Alliant Energy Corporation	1,000		31,200
Atmos Energy Corporation	800		22,096
Avista Corporation	500		10,190
Cleco Corporation	500		12,960
Consolidated Edison, Inc.	2,566		112,237
Energen Corporation	649		28,524
EQT Corporation	1,112		48,950
IDACORP, Inc.	400		12,540
MGE Energy, Inc.	201		6,719
National Fuel Gas Company	750		35,190
New Jersey Resources Corporation	400		14,596
Nicor, Inc.	400		16,208
NiSource, Inc.	2,500		35,625
Northeast Utilities	1,619		40,993
Northwest Natural Gas Company	243		10,539
NSTAR	978		33,585
OGE Energy Corporation	964		34,916
Pepco Holdings, Inc.	1,954		32,085
Piedmont Natural Gas Company, Inc.	630		16,172
Portland General Electric Company	815		15,892
Questar Corporation	1,559		64,667
UGI Corporation	974		23,873
WGL Holdings, Inc.	450		14,278
			698,738
Renewable Energy & Energy Efficiency — 1.2%
American Superconductor Corporation (a)	372		14,143
Applied Materials, Inc.	12,433		151,434
Calpine Corporation (a)	2,973		32,554
Cree, Inc. (a)	985		55,071
Energy Conversion Devices, Inc. (a)	450		4,100

15

GREEN CENTURY EQUITY FUND PORTFOLIO OF INVESTMENTS January 31, 2010 (unaudited) concluded

	SHARES	VALUE
Renewable Energy & Energy Efficiency — (continued)
First Solar, Inc. (a)	575	$	65,147
ITC Holdings Corporation	443		23,798
Itron, Inc. (a)	411		25,293
Johnson Controls, Inc.	6,183		172,073
Ormat Technologies, Inc.	164		5,645
SunPower Corporation, Class A (a)	538		10,970
Zoltek Companies, Inc. (a)	250		2,088
			562,316
Commercial & Professional Services — 0.7%
Avery Dennison Corporation	1,016		33,030
Deluxe Corporation	450		8,375
Herman Miller, Inc.	500		8,445
HNI Corporation	400		10,008
Interface, Inc., Class A	400		3,244
Kelly Services, Inc. (a)	200		2,624
Knoll, Inc.	420		4,729
Manpower, Inc.	723		37,444
Monster Worldwide, Inc. (a)	1,150		17,929
Pitney Bowes, Inc.	2,040		42,677
R.R. Donnelley & Sons Company	1,850		36,667
Robert Half International, Inc.	1,400		37,688
Steelcase, Inc.	500		3,540
Stericycle, Inc. (a)	766		40,544
Team, Inc. (a)	100		1,784
Tetra Tech, Inc. (a)	552		12,497
			301,225
Real Estate — 0.6%
AMB Property Corporation	1,295		31,080
Boston Properties, Inc.	1,285		83,358
CB Richard Ellis Group, Inc., Class A (a)	2,574		31,660
Forest City Enterprises, Inc., Class A (a)	1,339		15,144
Jones Lang LaSalle, Inc.	323		18,414
Liberty Property Trust	1,110		33,744
ProLogis	4,234		53,348
Regency Centers Corporation	809		27,094
			293,842

	SHARES	VALUE
Automobiles & Components — 0.2%
BorgWarner, Inc. (a)	1,150	$	40,354
Harley-Davidson, Inc.	2,166		49,255
Modine Manufacturing Company (a)	200		1,902
WABCO Holdings, Inc.	564		14,579
			106,090
Healthy Living — 0.1%
Hain Celestial Group, Inc. (The) (a)	350		5,596
United Natural Foods, Inc. (a)	400		10,844
Whole Foods Market, Inc. (a)	1,250		34,025
			50,465
Total Securities (Cost $48,006,495)			45,924,340
SHORT-TERM OBLIGATION — 0.5%
Repurchase Agreement— State Street Bank & Trust Repurchase Agreement, 0.01%, dated 01/29/10, due 02/01/10, proceeds $241,528 (collateralized by Federal Home Loan Bank, 4.375%, due 09/17/2010, value $249,936) (Cost $241,528)			241,528
TOTAL INVESTMENTS (b) — 100.2%
(Cost $48,248,023)			46,165,868
Liabilities Less Other Assets — (0.2)%			(90,088	)
NET ASSETS — 100.0%		$	46,075,780

(a) Non-income producing security.

(b) The cost of investments for federal income tax purposes is $49,656,706 resulting in gross unrealized appreciation and depreciation of $3,723,541 and $7,214,379 respectively, or net unrealized depreciation of $3,490,838.

See Notes to Financial Statements

16

GREEN CENTURY FUNDS STATEMENTS OF ASSETS AND LIABILITIES

January 31, 2010

(unaudited)

	BALANCED FUND			EQUITY FUND
ASSETS:
Investments, at value (cost $47,589,177 and $48,248,023 respectively)	$	50,346,882		$	46,165,868
Receivables for:
Capital stock sold		1,852			4,522
Interest		147,494			—
Dividends		33,929			46,826
Total assets		50,530,157			46,217,216
LIABILITIES:
Payable for securities purchased		—			94,420
Payable for capital stock repurchased		34,896			9,498
Accrued expenses		60,743			37,518
Total liabilities		95,639			141,436
NET ASSETS	$	50,434,518		$	46,075,780
NET ASSETS CONSIST OF:
Paid-in capital	$	66,184,749		$	55,171,178
Undistributed net investment income		34,198			13,855
Accumulated net realized losses on investments		(18,542,115	)		(7,027,098	)
Net unrealized appreciation (depreciation) on investments		2,757,686			(2,082,155	)
NET ASSETS	$	50,434,518		$	46,075,780
SHARES OUTSTANDING		3,263,054			2,673,910
NET ASSET VALUE, REDEMPTION PRICE AND OFFERING PRICE PER SHARE	$	15.46		$	17.23

GREEN CENTURY FUNDS STATEMENTS OF OPERATIONS

For the six-months ended January 31, 2010

(unaudited)

	BALANCED FUND			EQUITY FUND
INVESTMENT INCOME:
Interest income	$	377,175		$	12
Dividend and other income (net of $4,735 and $71 foreign withholding taxes, respectively)		243,658			421,210
Total investment income		620,833			421,222
EXPENSES:
Administrative services fee		184,178			162,318
Investment advisory fee		163,970			57,961
Total expenses		348,148			220,279
NET INVESTMENT INCOME		272,685			200,943
NET REALIZED AND UNREALIZED GAINS (LOSSES):
Net realized losses on investments:		(924,821	)		(859,128	)
Change in net unrealized appreciation on investments:		3,225,408			5,140,787
NET REALIZED AND UNREALIZED GAIN ON INVESTMENTS		2,300,587			4,281,659
NET INCREASE IN NET ASSETS RESULTING FROM OPERATIONS	$	2,573,272		$	4,482,602

See Notes to Financial Statements

17

GREEN CENTURY FUNDS STATEMENTS OF CHANGES IN NET ASSETS

	BALANCED FUND						EQUITY FUND
	FOR THE SIX MONTHS ENDED JANUARY 31, 2010 (UNAUDITED)			FOR THE YEAR ENDED JULY 31, 2009 (AUDITED)			FOR THE SIX MONTHS ENDED JANUARY 31, 2010 (UNAUDITED)			FOR THE YEAR ENDED JULY 31, 2009 (AUDITED)
INCREASE (DECREASE) IN NET ASSETS:
From operations:
Net investment income	$	272,685		$	864,319		$	200,943		$	522,974
Net realized losses on investments		(924,821	)		(5,067,782	)		(859,128	)		(5,948,753	)
Change in net unrealized appreciation (depreciation) on Investments		3,225,408			(416,403	)		5,140,787			(2,464,633	)
Net increase (decrease) in net assets resulting from operations		2,573,272			(4,619,866	)		4,482,602			(7,890,412	)
Dividends and distributions to shareholders:
From net investment income		(293,473	)		(871,482	)		(204,589	)		(552,199	)
From net realized gains		—			—			—			(11,945	)
Total dividends and distributions		(293,473	)		(871,482	)		(204,589	)		(564,144	)
Capital share transactions:
Proceeds from sales of shares		1,741,831			4,227,112			4,257,407			6,772,566
Reinvestment of dividends and distributions		287,026			849,276			201,951			558,869
Payments for shares redeemed		(1,978,662	)		(4,183,887	)		(3,320,258	)		(8,340,909	)
Net increase (decrease) in net assets resulting from capital share transactions		50,195			892,501			1,139,100			(1,009,474	)
Total increase (decrease) in net assets		2,329,994			(4,598,847	)		5,417,113			(9,464,030	)
NET ASSETS:
Beginning of period		48,104,524			52,703,371			40,658,667			50,122,697
End of period	$	50,434,518		$	48,104,524		$	46,075,780		$	40,658,667
Undistributed net investment income		34,198			54,986			13,855			17,501

See Notes to Financial Statements

18

GREEN CENTURY BALANCED FUND FINANCIAL HIGHLIGHTS

	SIX MONTHS ENDED JANUARY 31, 2010			FOR THE YEARS ENDED JULY 31,
	(UNAUDITED)			2009			2008			2007			2006			2005
Net Asset Value, beginning of period	$	14.75		$	16.52		$	17.78		$	16.29		$	16.52		$	14.11
Income from investment operations:
Net investment income		0.08			0.27			0.28			0.22			0.03			0.05
Net realized and unrealized gain (loss) on investments		0.72			(1.77	)		(1.27	)		1.48			(0.23	)		2.42
Total increase (decrease) from investment operations		0.80			(1.50	)		(0.99	)		1.70			(0.20	)		2.47
Less dividends:
Dividends from net investment income		(0.09	)		(0.27	)		(0.27	)		(0.21	)		(0.03	)		(0.06	)
Net Asset Value, end of period	$	15.46		$	14.75		$	16.52		$	17.78		$	16.29		$	16.52
Total return		5.41	%(a)		(8.88	)%		(5.62	)%		10.40	%		(1.22	)%		17.41	%
Ratios/Supplemental data:
Net assets, end of period (in 000’s)	$	50,435		$	48,105		$	52,703		$	51,754		$	50,230		$	62,449
Ratio of expenses to average net assets		1.38	%(b)		1.38	%		1.38	%		1.44	%		2.39	%		2.38	%
Ratio of net investment income to average net assets		1.08	%(b)		1.97	%		1.50	%		1.24	%		0.15	%		0.35	%
Portfolio turnover		13	%(a)		33	%		44	%		35	%		110	%		86	%

(a) Not annualized

(b) Annualized

GREEN CENTURY EQUITY FUND FINANCIAL HIGHLIGHTS

	SIX MONTHS ENDED JANUARY 31, 2010			FOR THE YEARS ENDED JULY 31,
	(UNAUDITED)			2009			2008			2007			2006			2005
Net Asset Value, beginning of period	$	15.65		$	18.83		$	22.66		$	19.91		$	19.91		$	18.18
Income from investment operations:
Net investment income		0.08			0.21			0.18			0.19			0.04			0.12
Net realized and unrealized gain (loss) on investments		1.58			(3.17	)		(2.81	)		2.75			(0.01	)		1.72
Total increase (decrease) from investment operations		1.66			(2.96	)		(2.63	)		2.94			0.03			1.84
Less dividends:
Dividends from net investment income		(0.08	)		(0.22	)		(0.19	)		(0.19	)		(0.03	)		(0.11	)
Distributions from net realized gains		—			—	(c)		(1.01	)		—			—			—
Total decrease from dividends		(0.08	)		(0.22	)		(1.20	)		(0.19	)		(0.03	)		(0.11	)
Net Asset Value, end of period	$	17.23		$	15.65		$	18.83		$	22.66		$	19.91		$	19.91
Total return		10.56	%(a)		(15.58	)%		(12.28	)%		14.76	%		0.16	%		10.10	%
Ratios/Supplemental data:
Net assets, end of period (in 000’s)	$	46,076		$	40,659		$	50,123		$	42,232		$	32,938		$	35,383
Ratio of expenses to average net assets		0.95	%(b)		0.95	%		0.95	%		0.95	%		1.50	%		1.50	%
Ratio of net investment income to average net assets		0.87	%(b)		1.38	%		0.98	%		0.89	%		0.20	%		0.64	%
Portfolio turnover		9	%(a)		23	%		6	%		8	%(d)		12	%(e)		9	%(e)

(a) Not annualized.

(b) Annualized.

(c) Amount represents less than 0.005 per share.

(d) Represents portfolio turnover for the Equity Fund from November 28, 2006 to July 31, 2007. Porfolio turnover for the Domini Trust from August 1, 2006 to November 27, 2006 was 1%. For further information regarding the withdrawal of the Equity Fund’s investment in the Domini Trust, please see the notes to the financial statements.

(e) Represents portfolio turnover for the Domini Social Equity Trust (“Domini Trust”) for the years ended 2006 and 2005.

See Notes to Financial Statements

19

GREEN CENTURY FUNDS NOTES TO FINANCIAL STATEMENTS

(unaudited)

NOTE 1 — Organization and Significant Accounting Policies

Green Century Funds (the “Trust”) is a Massachusetts business trust which offers two separate series, the Green Century Balanced Fund (the “Balanced Fund”) and the Green Century Equity Fund (the “Equity Fund”), collectively, the “Funds”. The Trust is registered under the Investment Company Act of 1940, as amended (the “Act”), as an open-end management investment company. The Trust accounts separately for the assets, liabilities and operations of each series. The Balanced Fund commenced operations on March 18, 1992 and the Equity Fund commenced operations on September 13, 1995.

Through November 27, 2006, the Equity Fund invested substantially all of its assets in the Domini Social Equity Trust (the “Domini Trust”), an open-end, diversified management investment company which had the same investment objective as the Fund. The Equity Fund accounted for its investment in the Domini Trust as a partnership investment and recorded its share of the Domini Trust income, expenses and realized and unrealized gains and losses daily. The value of such investment reflected the Fund’s proportionate interest in the net assets of the Domini Trust (2.57% at November 27, 2006). Effective November 28, 2006, the Equity Fund withdrew its investment from the Domini Trust and directly invested in the securities of the companies included in the FTSE KLD 400 Social Index, formerly the Domini 400 Social^SM Index (the “Index”).

The preparation of financial statements in conformity with U.S. generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.

The following is a summary of the Funds’ significant accounting policies:

(A) Investment Valuation:    Equity securities listed on national securities exchanges other than NASDAQ are valued at last sale price. If a last sale price is not available, securities listed on national exchanges other than NASDAQ are valued at the mean between the closing bid and closing ask prices. NASDAQ National Market^® and SmallCap^SM securities are valued at the NASDAQ Official Closing Price (“NOCP”). The NOCP is based on the last traded price if it falls within the concurrent best bid and ask prices and is normalized pursuant to NASDAQ’s published procedures if it falls outside this range. If a NOCP is not available for any such security, the security is valued at the last sale price, or, if there have been no sales that day, at the mean between the closing bid and closing ask prices. Unlisted equity securities are valued at last sale price, or when last sale prices are not available, at the last quoted bid price. Debt securities (other than certificates of deposit and short-term obligations maturing in sixty days or less) are valued on the basis of valuations furnished by a pricing service which takes into account appropriate factors such as institution-size trading in similar groups of securities, yield, quality, coupon rate, maturity, type of issue, and other market data, without exclusive reliance on quoted prices or exchange or over-the-counter prices, since such valuations are believed to reflect more accurately the fair value of the securities. Securities, if any, for which there are no such valuations or quotations available, or for which the market quotation is not reliable, are valued at fair value by management as determined in good faith under guidelines established by the Trustees. Certificates of deposit are valued at cost plus accrued interest. Short-term obligations maturing in sixty days or less are valued at amortized cost, which approximate market value.

20

GREEN CENTURY FUNDS NOTES TO FINANCIAL STATEMENTS (unaudited) continued

Various inputs are used in determining the value of the Fund’s investments. These inputs are summarized in the three broad levels listed below:

Level 1 — quoted prices for active markets for identical securities. An active market for the security is a market in which transactions occur with sufficient frequency and volume to provide pricing information on an ongoing basis. A quoted price in an active market provides the most reliable evidence of fair value.

Level 2 — other significant observable inputs (including quoted prices for similar securities, interest rates, prepayment speeds, credit risk, etc.) Quoted prices for identical or similar assets in markets that are not active. Inputs that are derived principally from or corroborated by observable market data. An adjustment to any observable input that is significant to the fair value may render the measurement a Level 3 measurement.

Level 3 — significant unobservable inputs, including the Fund’s own assumptions in determining the fair value of investments.

The inputs or methodology used for valuing securities are not necessarily an indication of the risk associated with investing in those securities.

The following is a summary of the inputs used to value the Balanced Fund’s net assets as of January 31, 2010:

	LEVEL 1 — QUOTED PRICES	LEVEL 2 — OTHER SIGNIFICANT OBSERVABLE INPUTS	LEVEL 3 — SIGNIFICANT UNOBSERVABLE INPUTS	TOTAL
COMMON STOCKS*	$32,322,906	$            —	$            —	$32,322,906
CORPORATE BONDS & NOTES	—	11,643,713	—	11,643,713
U.S. GOVERNMENT AGENCIES	—	4,774,035	—	4,774,035
CERTIFICATES OF DEPOSIT	—	190,025	—	190,025
SHORT-TERM OBLIGATION	—	1,416,203	—	1,416,203
TOTAL	$32,322,906	$18,023,976	$            —	$50,346,882

* All sub-categories within common stocks represent level 1 evaluation status.

The following is a summary of the inputs used to value the Equity Fund’s net assets as of January 31, 2010:

	LEVEL 1 — QUOTED PRICES	LEVEL 2 — OTHER SIGNIFICANT OBSERVABLE INPUTS	LEVEL 3 — SIGNIFICANT UNOBSERVABLE INPUTS	TOTAL
COMMON STOCKS*	$45,924,340	$       —	$            —	$45,924,340
SHORT-TERM OBLIGATION	—	241,528	—	241,528
TOTAL	$45,924,340	$241,528	$            —	$46,165,868

* All sub-categories within common stocks represent level 1 evaluation status.

21

GREEN CENTURY FUNDS NOTES TO FINANCIAL STATEMENTS (unaudited) continued

In preparing these financial statements, management has evaluated events and transactions for potential recognition or disclosure through the date on which the financial statements were issued.

(B) Securities Transactions and Investment Income:    Securities transactions are recorded on a trade date basis. Realized gains and losses from securities transactions are determined using the identified cost basis. Interest income, including amortization of premiums and accretion of discounts on bonds, is recognized on the accrual basis and dividend income is recorded on ex-dividend date.

(C) Options Transactions:    The Balanced Fund may utilize options to hedge or protect from adverse movements in the market values of its portfolio securities and to enhance return. The Equity Fund may utilize options to hedge against possible increases in the value of securities which are expected to be purchased by the Equity Fund or possible declines in the value of securities which are expected to be sold by the Equity Fund. The use of options may involve risks such as the possibility of illiquid markets or imperfect correlation between the value of the option and the underlying securities. The Funds may write put or call options. Premiums received upon writing put or call options are recorded as an asset with a corresponding liability which is subsequently adjusted to the current market value of the option. Changes between the initial premiums received and the current market value of the options are recorded as unrealized gains or losses. When an option is closed, expired or exercised, a gain or loss is realized and the liability is eliminated. The Funds continue to bear the risk of adverse movements in the price of the underlying assets during the period of the option, although any potential loss during the period would be reduced by the amount of the option premium received. As required by the Act, liquid securities are designated as collateral in an amount equal to the market value of open options contracts.

(D) Repurchase Agreements:    The Funds may enter into repurchase agreements with selected banks or broker-dealers that are deemed by the Funds’ adviser to be creditworthy pursuant to guidelines established by the Board of Trustees. Each repurchase agreement is recorded at cost, which approximates fair value. The Funds require that the market value of collateral, represented by securities (primarily U.S. Government securities), be sufficient to cover payments of interest and principal and that the collateral be maintained in a segregated account with a custodian bank in a manner sufficient to enable the Funds to obtain those securities in the event of a default of the counterparty. In the event of default or bankruptcy by the counterparty to the repurchase agreement, retention of the collateral may be subject to legal proceedings.

(E) Distributions:    Distributions to shareholders are recorded on the ex-dividend date. The Funds declare and pay dividends of net investment income, if any, semi-annually and distribute net realized capital gains, if any, annually. The amount and character of income and net realized gains to be distributed are determined in accordance with Federal income tax rules and regulations, which may differ from U.S. generally accepted accounting principles. To the extent that these differences are attributable to permanent book and tax accounting differences, the components of net assets have been adjusted.

(F) Federal Taxes:    Each series of the Trust is treated as a separate entity for Federal income tax purposes. Each Fund’s policy is to comply with the provisions of the Internal Revenue Code applicable to regulated investment companies. Accordingly, no provisions for Federal income or excise tax are necessary.

In July 2006, the Financial Accounting Standards Board (FASB) issued Accounting for Uncertainty in Income Taxes. This interpretation addresses the accounting for uncertainty in income taxes and establishes for all entities, including pass-through entities such as the Funds, a minimum threshold for financial statement recognition of the benefit of positions taken in filing tax returns (including whether an entity is taxable in a particular jurisdiction). The Funds recognize tax benefits only if it is more likely than not that a tax position (including the Funds’ assertion that their income is exempt from tax) will be sustained upon examination.

22

GREEN CENTURY FUNDS NOTES TO FINANCIAL STATEMENTS (unaudited) continued

The Funds adopted Accounting for Uncertainty in Income Taxes in fiscal year 2008. The Funds had no material uncertain tax positions and have not recorded a liability for unrecognized tax benefits as of January 31, 2010. Also, the Funds had recognized no interest and penalties related to uncertain tax benefits through January 31, 2010. At January 31, 2010, the tax years 2006 through 2010 remain open to examination by the Internal Revenue Service.

(G) Redemption Fee:    A 2.00% redemption fee is retained by the Funds to offset the effect of transaction costs and other expenses associated with short-term investing. The fee is imposed on redemptions or exchanges of shares held 60 days or less from their purchase date. For the six months ended January 31, 2010, the Balanced Fund and Equity Fund received $569 and $234, respectively, in redemption fees. Redemption fees are recorded as an adjustment to paid-in capital.

NOTE 2 — Transactions With Affiliates

(A) Investment Adviser:    Green Century Capital Management, Inc. (“Green Century”) is the adviser (“the Adviser”) for the Funds. Green Century is owned by Paradigm Partners. Green Century oversees the portfolio management of the Funds on a day-to-day basis. The Balanced Fund pays Green Century a fee, accrued daily and paid monthly, at an annual rate equal to 0.65% of the Balanced Fund’s average daily net assets. The Equity Fund pays Green Century a fee, accrued daily and paid monthly, at an annual rate of 0.25% of the Equity Fund’s average daily net assets up to but not including $100 million, 0.22% of average daily net assets including $100 million up to but not including $500 million, 0.17% of average daily net assets including $500 million up to but not including $1 billion and 0.12% of average daily net assets equal to or in excess of $1 billion.

(B) Subadvisers:    Trillium Asset Management Corporation (“Trillium”) is the subadviser for the Balanced Fund. Trillium is paid a fee by the Adviser at an annual rate of 0.40% on the first $30 million of average daily net assets and 0.35% on average daily net assets in excess of $30 million for its services. For the six months ended January 31, 2010, Green Century accrued fees of $95,853 to Trillium. Mellon Capital Management Corporation (“Mellon”) is the subadviser for the Equity Fund. Mellon is paid a fee by the Adviser the greater of $50,000 or 0.08% of the value of the average daily net assets of the Fund up to but not including $100 million, 0.05% of the average daily net assets of the Fund from and including $100 million up to but not including $500 million, 0.02% of the average daily net assets of the Fund from and including $500 million up to but not including $1 billion and 0.01% of the average daily net assets of the Fund equal to or in excess of $1 billion for its services. For the six months ended January 31, 2010, Green Century accrued fees of $25,205 to Mellon.

(C) Administrator:    Green Century is the administrator (“the Administrator”) of the Green Century Funds. Pursuant to the Administrative Services Agreement, Green Century pays all the expenses of each Fund other than the investment advisory fees; interest; taxes; brokerage costs and other capital expenses; expenses of non-interested trustees (including counsel fees) and any extraordinary expenses. The Balanced Fund pays Green Century a fee at a rate such that immediately following any payment to the Administrator, the total operating expenses of the Fund, on an annual basis, do not exceed 1.38% of the Fund’s average daily net assets. The Equity Fund pays Green Century a fee at a rate such that immediately following any payment to the Administrator, the total operating expenses of the Fund, on an annual basis, do not exceed 0.95% of the Fund’s average daily net assets.

(D) Subadministrator:    Pursuant to a Subadministrative Services Agreement with the Administrator, UMB Fund Services, Inc. (“UMBFS”) as Subadministrator, is responsible for conducting certain day-to-day

23

GREEN CENTURY FUNDS NOTES TO FINANCIAL STATEMENTS (unaudited) continued

administration of the Trust subject to the supervision and direction of the Administrator. For the six months ended January 31, 2010, Green Century accrued fees of $44,275 and $44,275 to UMBFS related to services performed on behalf of the Balanced Fund and the Equity Fund, respectively.

(E) Index Agreement:    The Equity Fund invests in the securities of the companies included in the Index. The Index is owned and maintained by KLD Research and Analytics, Inc. (“KLD”), a subsidiary of RiskMetrics Group, Inc. For the use of the Index, KLD is paid a fee by the Adviser the greater of $50,000 or at an annual rate of 0.10% on the first $500 million of average daily net assets, 0.075% on average daily net assets on the next $500 million, and 0.05% on average daily net assets in excess of $1 billion. For the six months ended January 31, 2010, Green Century accrued fees of $25,205 to KLD.

NOTE 3 — Investment Transactions

The Balanced Fund’s cost of purchases and proceeds from sales of securities, other than short-term securities, aggregated $6,349,143 and $6,438,671, respectively, for the six months ended January 31, 2010. The Equity Fund’s cost of purchases and proceeds from sales of securities, other than short-term securities, aggregated $5,212,161 and $4,077,383, respectively.

NOTE 4 — Federal Income Tax Information

The tax basis of the components of distributable net earnings (deficit) at July 31, 2009 were as follows:

	BALANCED FUND			EQUITY FUND
Undistributed ordinary income	$	54,986		$	15,949
Undistributed long-term capital gains		—			—
Tax accumulated earnings		54,986			15,949
Accumulated capital and other losses		(17,614,040	)		(4,975,365	)
Unrealized depreciation		(471,041	)		(8,413,995	)
Unrealized appreciation on foreign currency		65			—
Distributable net earnings (deficit)	$	(18,030,030	)	$	(13,373,411	)

The Balanced Fund and the Equity Fund had accumulated capital loss carryforwards of $13,559,919 and $1,484,742, respectively, of which $2,323,170 and $0, respectively, expire in the year 2010, $9,370,230 and $0, respectively, expire in the year 2011 and $1,866,519 and $1,484,742, respectively, expire in the year 2017. To the extent that a Fund realizes future net capital gains, those gains will be offset by any unused capital loss carryforwards.

At July 31, 2009, the Balanced and Equity Fund had net realized capital losses from transactions between November 1, 2008 and July 31, 2009 of $4,054,121 and $3,490,623, respectively, which for tax purposes, are deferred and will be recognized in fiscal year 2010.

24

GREEN CENTURY FUNDS NOTES TO FINANCIAL STATEMENTS (unaudited) concluded

The tax character of distributions paid during the fiscal years ended July 31, 2009 and July 31, 2008 were as follows:

	BALANCED FUND				EQUITY FUND
	YEAR ENDED JULY 31, 2009		YEAR ENDED JULY 31, 2008		YEAR ENDED JULY 31, 2009		YEAR ENDED JULY 31, 2008
Ordinary income	$	871,482	$	818,386	$	563,381	$	416,913
Long-term capital gains		—		—		763		1,920,696

NOTE 5 — Capital Share Transactions

Capital Share transactions for the Balanced Fund and the Equity Fund were as follows:

	BALANCED FUND				EQUITY FUND
	SIX MONTHS ENDED JANUARY 31, 2010		YEAR ENDED JULY 31, 2009		SIX MONTHS ENDED JANUARY 31, 2010		YEAR ENDED JULY 31, 2009
Shares sold	113,311		312,356		259,125		483,492
Reinvestment of dividends	17,997		63,489		11,175		39,711
Shares redeemed	(128,691	)	(305,478	)	(194,231	)	(586,619	)
	2,617		70,367		76,069		(63,416	)

25

BOARD OF TRUSTEES’ CONSIDERATION OF ADVISORY AND SUBADVISORY AGREEMENTS

The Board of Trustees of the Green Century Funds considered and approved the continuance of four advisory and subadvisory agreements during the six months ended January 31, 2010.

INVESTMENT ADVISORY AGREEMENTS WITH GREEN CENTURY CAPITAL MANAGEMENT, INC.

The Board, including the Independent Trustees, approved the continuance of the Investment Advisory Agreements (the “Advisory Agreements”) between the Trust, on behalf of the Balanced Fund and the Equity Fund (the “Funds” and each a “Fund”), and Green Century Capital Management (“Green Century” or the “Adviser”), at a meeting on September 25, 2009. In connection with their deliberations at the meeting, and in separate executive session of the Independent Trustees, the Trustees considered, among other things, information provided by Green Century regarding the investment performance of each Fund; the expenses of each Fund and the advisory fee to be paid to Green Century by each Fund; and the profitability to Green Century of its proposed advisory relationship to each Fund. The Independent Trustees were assisted by independent counsel in considering these materials and the approval and continuance of the Advisory Agreements. The Trustees considered all the information provided to them by Green Century, including information provided throughout the year. In approving the Advisory Agreements, the Board, including the Independent Trustees, did not identify any single factor as determinative. Matters considered in connection with their approval of the Advisory Agreements included the following.

Nature, Quality, and Extent of Services Performed.    The Trustees considered the scope and quality of the services to be performed for each of the Funds by the Adviser, including the resources to be dedicated by the Adviser. With respect to the Equity Fund, these services included monitoring the Equity Fund’s performance and tracking error relative to the FTSE KLD 400 Social Index (the “Index”); implementing the environmental policies of the Trust by voting the Equity Fund’s shareholder proxies; and overall compliance oversight provided by the Adviser. With respect to the Balanced Fund, the services performed included the oversight and monitoring of the portfolio management and performance of the Balanced Fund; monitoring the implementation of the Balanced Fund’s environmental screens; implementing the environmental policies of the Trust by voting the Balanced Fund’s shareholder proxies; and overall compliance oversight provided by the Adviser. In addition, the Trustees considered the administrative services provided by the Adviser to both Funds, including the coordination of the activities of all of the Funds’ other service providers.

Based on its review of all of the services provided, the Trustees concluded that the nature, quality and extent of services provided by the Adviser supported the continuance of the Advisory Agreements with respect to the Equity Fund and the Balanced Fund.

Investment Performance.    With respect to the Equity Fund, the Trustees considered that due to the Equity Fund’s passive investment strategy, the principal concern with regard to investment performance was the extent to which the Equity Fund tracked the Index and noted that the Equity Fund’s performance closely followed that of the Index for the period ended August 31, 2009. After considering all the factors deemed appropriate, the Trustees, including the Independent Trustees, concluded that the performance of the Equity Fund supported the continuance of the Advisory Agreement with respect to the Equity Fund.

With respect to the Balanced Fund, the Trustees reviewed and considered information regarding the investment performance of the Balanced Fund and comparative data with respect to the performance of other funds designated by Morningstar to have similar investment objectives as well as the Balanced Fund’s performance measured against the Lipper Balanced Fund Index, a broad-based balanced fund market index.

26

The Trustees noted that as of the period ended August 31, 2009, the Balanced Fund’s ten-year average annual return had outperformed the Lipper Balanced Fund Index, while the Balanced Fund’s one-, three-, and five-year average annual returns had underperformed the benchmark. The Trustees also considered the performance information they had been provided throughout the year. After considering all the factors deemed appropriate, the Trustees, including the Independent Trustees, concluded that the performance of the Balanced Fund supported the continuance of the Advisory Agreement with respect to the Balanced Fund.

The Costs of Services Provided and Profitability.    The Trustees considered the costs of the services provided to the Funds and the profitability and fall-out benefits to the Adviser from its arrangements with the Funds.

The Trustees reviewed and considered an analysis of the advisory fees and total expenses ratios of each Fund and comparative data for multiple categories of mutual funds included in and as defined by Morningstar’s mutual fund database of over 7,000 mutual funds. For the Equity Fund, the Trustees noted that, based on the information provided, the Fund’s advisory fee was lower than the average advisory fee for socially conscious funds by 36 basis points and lower than that of the average growth and income funds by 21 basis points. The Trustees also noted that the total expense ratio of the Equity Fund of 0.95% was lower than that of the average of socially responsible funds by 22 basis points and lower than that of the average of all growth and income funds by 3 basis points. The Trustees considered that the Equity Fund is an index fund, whereas many of the funds in the comparison groups are actively managed. For the Balanced Fund, the Trustees noted that, based on the information provided, the Fund’s advisory fee was higher than the average advisory fee for socially conscious funds (by 4 basis points), socially conscious balanced Funds (by 10 basis points), all balanced funds (by 18 basis points) and balanced funds which have under $100 million in assets (by 14 basis points). The Trustees considered that Green Century had reduced its advisory fee by 10 basis points in 2006. The Trustees also noted that the total expense ratio of the Balanced Fund was capped at 1.38% and that the total expense ratio was higher than that of the average of socially responsible funds by 21 basis points, higher than that of the average of all balanced funds by 31 basis points, and higher than that of the average of balanced funds with assets less than $100 million by 19 basis points.

Green Century provided the Trustees with information relating to the profitability to Green Century of its advisory relationships to the Funds. The Trustees noted that based on information provided by Green Century, the relationship was not profitable. In that regard, the Trustees considered the subadvisory fees and the other expenses incurred by the Adviser in providing advisory services to the Funds. The Trustees also considered the fee received by Green Century for providing administrative services to the Funds and the expenses incurred in providing those services. In considering the cost allocation methodology used by Green Century, the Trustees took into consideration that the Adviser does not provide advisory or administrative services to other mutual funds or non-mutual fund clients. The Trustees also considered Green Century’s non-profit ownership structure, its cost structure and personnel needs, and its investment in shareholder advocacy to further the Funds’ stated objective of promoting greater corporate environmental accountability. After reviewing the information described above, the Independent Trustees concluded that the fees specified in the Advisory Agreements, taking into account the costs of the services provided by the Adviser and the profitability to the Adviser of its relationships with the Funds, supported the continuance of the Advisory Agreements with respect to the Equity Fund and the Balanced Fund.

Other Benefits.    With respect to fall-out benefits, the Trustees considered that neither Green Century nor any affiliate of Green Century receives any brokerage fees, soft dollar benefits, liquidity rebates from electronic communications networks or payments for order flow from the trades executed for either Fund. The Trustees noted that Green Century does benefit intangibly from its relationship with the Funds due to the Funds’ reputation as the first family of no-load environmentally responsible mutual funds. Further, pursuant to the Advisory Agreements, Green Century has reserved for itself the rights to the names “Green Century Funds” and any similar names; thus, Green Century may benefit in the future from developing other funds or investment products with the Green Century brand. The Trustees concluded that

27

the fall-out benefits to be realized by Green Century were appropriate and supported the continuance of the Advisory Agreements with respect to the Equity Fund and the Balanced Fund.

Economies of Scale.    The Trustees also considered whether economies of scale could be realized by the Adviser as the Funds grew in asset size and the extent to which such economies of scale were reflected in the level of fees charged. They noted the relatively small size of each Fund and the resultant difficulty of achieving meaningful economies of scale. They considered that if the assets were to increase, the Funds could have the opportunity to experience economies of scale as fixed costs would become a smaller percentage of the Funds’ assets and some of the Funds’ service providers’ fees, as a percentage of the Funds’ assets, could decrease. The Trustees noted that the subadvisory fee structure for the Equity Fund included break-points and that the Equity Fund’s advisory fee would decrease as assets increased. The Trustees concluded that economies of scale could be realized as the Funds grew and that if assets increased significantly the Trustees would have opportunities to negotiate decreases in fees with the Adviser.

Based on a review of all factors deemed relevant, the Trustees, including the Independent Trustees, concluded that the Advisory Agreements with respect to the Balanced Fund and the Equity Fund should be continued for an additional one-year period.

INVESTMENT SUBADVISORY AGREEMENT WITH TRILLIUM ASSET MANAGEMENT CORPORATION RELATING TO THE BALANCED FUND

At the meeting on September 25, 2009, the Board of Trustees of the Balanced Fund, including a majority of the Independent Trustees, considered the continuance of the subadvisory agreement between the Trust, on behalf of the Balanced Fund, Green Century, and Trillium Asset Management Corporation (“Trillium”) (the “Subadvisory Agreement”). In connection with their deliberations at the meeting, and in separate executive session of the Independent Trustees, the Trustees considered, among other things, information provided by Trillium regarding the investment performance of the Balanced Fund, the subadvisory fees paid to Trillium, and the profitability to Trillium of its subadvisory relationship to the Balanced Fund. The Independent Trustees were assisted by independent counsel in considering these materials and the continuance of the Subadvisory Agreement. The Trustees considered all the information provided to them by Trillium, including information provided throughout the year. In approving the continuance of the Subadvisory Agreement, the Board, including the Independent Trustees, did not identify any single factor as determinative. Matters considered in connection with their approval of the Subadvisory Agreement included the following.

Nature, Quality, and Extent of Services Performed.    The Trustees noted that under the terms of the Subadvisory Agreement, Trillium provided the day-to-day portfolio management of the Balanced Fund, including determining asset and sector allocation; conducting securities selection and discovery; researching and analyzing environmental policies and practices of companies and implementing the Balanced Fund’s environmental screening criteria; managing volatility, risk, and portfolio turnover; and investing the portfolio consistent with the Balanced Fund’s investment objective and policies. The Trustees considered the professional expertise, tenure, and qualifications of the portfolio management team and noted that Trillium was devoted exclusively to environmentally and socially responsible investing and managed approximately $825 million in assets. The Trustees also considered Trillium’s compliance record as well as the professional experience and responsiveness of Trillium’s compliance staff. The Trustees also considered Trillium's leadership in social and environmental responsibility, including its shareholder advocacy efforts.

Based on its review of all of the services provided and to be provided, the Trustees concluded that the nature, quality and extent of services provided by Trillium supported the continuance of the Subadvisory Agreement.

Investment Performance.    The Trustees reviewed and considered information regarding the investment performance of the Balanced Fund and comparative data with respect to the performance of mutual funds with similar investment

28

objectives as well as other broad-based market indexes. The Trustees noted that as of the period ended August 31, 2009, the Balanced Fund’s ten-year return outperformed the Lipper Balanced Fund Index, while the one-, three-, and five-year return had underperformed the Lipper Index. Trillium became the Balanced Fund’s subadviser on November 28, 2005. The Trustees also considered the Balanced Fund’s decrease in volatility in the four years since Trillium became the Balanced Fund’s subadviser. After considering all the factors deemed appropriate, the Trustees concluded that the performance of the Balanced Fund together with Trillium’s investment process, philosophies and experience in environmentally and socially responsible investing supported the continuance of the Subadvisory Agreement.

Costs of Services Provided and Profitability.    The Trustees considered that the subadvisory fees paid by Green Century to Trillium under the Subadvisory Agreement were 0.40% of the value of the average daily net assets of the Balanced Fund up to $30 million, and 0.35% of the value of the average daily net assets of the Balanced Fund in excess of $30 million. The Trustees reviewed the subadvisory fees against comparative data for multiple categories of mutual funds presented in various categories: socially conscious funds, all balanced funds, and balanced funds of under $100 million in assets. The Trustees noted that, based on the information provided, the subadvisory fees were within two basis points of the average subadvisory fees for all socially conscious funds, all balanced funds and balanced funds of under $100 million in assets. The Trustees also noted that the subadvisory fees are paid by Green Century, and are not in addition to the advisory fees paid to Green Century by the Balanced Fund.

In evaluating the profitability of the Subadvisory Agreement to Trillium, the Trustees noted that based on information provided by Trillium, the relationship was not profitable. The Trustees noted that Trillium stated that it would not realize a level of profitability similar to that of its other advisory clients on the management of the Balanced Fund until assets approach $115 million. The Trustees considered the financial resources Trillium dedicated and the other expenses Trillium incurred in providing subadvisory services to the Balanced Fund, including startup costs relating to the relationship, and additional personnel, legal, trading analysis and compliance costs required in the context of providing subadvisory services to a mutual fund. In considering the cost allocation methodology used by Trillium, the Trustees took under consideration that Trillium does not provide advisory or subadvisory services to other mutual fund clients. The Trustees also considered Trillium’s fee structure and noted, based on the information provided, that the subadvisory fees were lower than the fees Trillium charges its institutional separate account clients.

After reviewing the information described above, the Trustees concluded that the fees specified in the Subadvisory Agreement, taking into account the nature and quality of services provided and the costs of the services provided by Trillium, supported the continuance of the Subadvisory Agreement.

Other Benefits.    The Trustees evaluated potential other benefits Trillium may realize from its relationship with the Balanced Fund. The Trustees considered the brokerage practices of Trillium, including the soft dollar commissions that were generated with respect to the Balanced Fund’s portfolio transactions. The Trustees considered that Trillium was not affiliated with a broker/dealer and therefore no benefit would be realized by Trillium through transactions with affiliated brokers. The Trustees also considered the reputational and other advantages Trillium may gain from its relationship with the Balanced Fund. The Trustees concluded that the benefits received by Trillium were reasonable in the context of the relationship between Trillium and the Balanced Fund, and supported the continuance of the Subadvisory Agreement.

Economies of Scale.    The Trustees also considered whether economies of scale would be realized by Trillium as the Balanced Fund grew in asset size and the extent to which such economies of scale might be reflected in the subadvisory fees. They noted the relatively small size of the Balanced Fund and considered that if the assets were to increase, Trillium could have the opportunity to experience economies of scale. They also noted that pursuant to the Subadvisory Agreement, the subadvisory fees paid to Trillium by Green Century include a breakpoint at $30 million, so that fees as a percentage of net assets decrease as assets in the Balanced Fund increase. The Trustees concluded that economies of

29

scale could be realized as the Fund grew, and that the fee schedule as specified was appropriate, and supported the continuance of the Subadvisory Agreement.

Based on a review of all factors deemed relevant, the Trustees, including the Independent Trustees, concluded that the Subadvisory Agreement should be continued for an additional one-year period.

INVESTMENT SUBADVISORY AGREEMENT WITH MELLON CAPITAL MANAGEMENT RELATING TO THE EQUITY FUND

Also at the meeting on September 25, 2009, the Board of Trustees of the Equity Fund, including a majority of the Independent Trustees, considered the continuance of the subadvisory agreement between the Trust, on behalf of the Equity Fund, Green Century, and Mellon Capital Management (“Mellon”) (the “Subadvisory Agreement”). In connection with their deliberations at the meeting, and in separate executive session of the Independent Trustees, the Trustees considered, among other things, information provided by Mellon regarding the investment performance of the Equity Fund, including the success with which the Fund tracked the Index, the subadvisory fees paid to Mellon, and the profitability to Mellon of its subadvisory relationship to the Equity Fund. The Independent Trustees were advised by independent counsel in considering these materials and the continuance of the Subadvisory Agreement. The Trustees considered all the information provided to them by Mellon, including information provided throughout the year. In approving the continuance of the Subadvisory Agreement, the Board, including the Independent Trustees, did not identify any single factor as determinative. Matters considered in connection with their approval of the Subadvisory Agreement included the following.

Nature, Quality, and Extent of Services Performed.    The Trustees noted that under the terms of the Subadvisory Agreement, Mellon provided the day-to-day portfolio management of the Equity Fund, making purchases and sales of portfolio securities consistent with the Equity Fund’s investment objective and policies and with changes to the Index. The Trustees considered the professional expertise, tenure, and qualification of the portfolio management team for the Equity Fund, as well as the team’s experience in passive management. The Trustees also considered Mellon’s handling of daily inflows and outflows, transaction costs, tracking error, and the portfolio turnover rates for the Equity Fund. The Trustees also considered Mellon’s compliance record as well as the professional experience and responsiveness of Mellon’s compliance staff.

Based on its review of all of the services provided, the Trustees concluded that the nature, quality and extent of services provided by Mellon supported the continuance of the Subadvisory Agreement.

Investment Performance.    The Trustees considered that the Equity Fund follows a passive investment strategy designed to track the Index and therefore the analysis of its investment performance should be based on the extent to which the Equity Fund successfully tracked the Index. The Trustees reviewed the performance of the Equity Fund, exclusive of the expenses of the fund, as compared to that of the Index for the periods ended August 31, 2009. After considering all the factors deemed appropriate, the Trustees concluded that the performance of the Equity Fund together with Mellon’s investment process and experience in passive portfolio management supported the continuance of the Subadvisory Agreement.

Costs of Services Provided and Profitability.    The Trustees considered that the subadvisory fees paid by Green Century to Mellon were 0.08% of the value of the average daily net assets of the Equity Fund up to $100 million, 0.05% of the value of the average daily net assets of the Equity Fund from $100 to $500 million, 0.02% of the value of the average daily net assets of the Equity Fund from $500 million to $1 billion, and 0.01% of the value of the average daily net assets of the Equity Fund in excess of $1 billion, subject to a minimum fee of $50,000 per year. The Trustees reviewed and considered an analysis of the subadvisory fees against comparative data for multiple categories of mutual funds. The Trustees noted that, based on the information provided, the subadvisory fees paid to Mellon were lower than the average subadvisory fees paid to subadvisers of socially conscious funds, socially conscious growth and income funds,

30

all growth and income funds and growth and income funds under $100 million in assets. The Trustees considered that the Equity Fund is an index fund, whereas many of the funds in the comparison groups are actively managed. The Trustees also noted that the subadvisory fees are paid by Green Century, and are not in addition to the advisory fees paid to Green Century by shareholders.

Green Century provided the Trustees with information prepared by Mellon related to the profitability of the Subadvisory Agreement. The Trustees considered the subadvisory fees and the financial resources Mellon dedicates and the other expenses it incurs in providing subadvisory services to the Equity Fund. In considering the cost allocation methodology used by Mellon, the Trustees noted that Mellon allocated its costs to all its clients equally although Mellon stated that passively managed accounts are less expensive to service than actively managed accounts. The Trustees noted that based on the information provided by Mellon, the relationship was not profitable to Mellon.

After reviewing the information described above, the Trustees concluded that the fees specified in the Subadvisory Agreement, taking into account the costs of the services provided by Mellon, supported the continuance of the Subadvisory Agreement. The Trustees also concluded that the fees specified in the Subadvisory Agreement were fair and reasonable in light of the usual and customary charges made by others for services of the same nature and quality.

Other Benefits.    The Trustees evaluated other potential benefits Mellon may realize from its relationship with the Equity Fund. The Trustees considered the brokerage practices of Mellon, including Mellon’s policy that it does not execute transactions for client portfolios through any affiliated broker/dealer and thus no benefit would be realized by Mellon through transactions with affiliated brokers. The Trustees also considered that Mellon does not use trades for index portfolios for the generation of soft dollars, nor does Mellon receive liquidity rebates or payment for order flow from electronic communications networks associated with Equity Fund trades. The Trustees further considered the reputational and other advantages Mellon may gain from its relationship with the Equity Fund. The Trustees concluded that the benefits expected to be received by Mellon were reasonable in the context of the relationship between Mellon and the Equity Fund, and supported the continuance of the Subadvisory Agreement.

Economies of Scale.    The Trustees also considered whether economies of scale would be realized by Mellon as the Equity Fund grew in assets and the extent to which such economies of scale might be reflected in the specified fee schedule. They noted the relatively small size of the Equity Fund and considered that if the assets were to increase, Mellon could have the opportunity to experience economies of scale. They also noted that pursuant to the Subadvisory Agreement, the subadvisory fees specified paid to Mellon by Green Century include breakpoints at $100 million, $500 million, and $1 billion.

Based on the foregoing considerations, the Trustees, including the Independent Trustees, determined that the Subadvisory Agreement should be continued for an additional one-year period.

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Semi-Annual Report

INVESTMENT ADVISER AND ADMINISTRATOR

Green Century Capital Management, Inc.

114 State Street

Boston, MA 02109

1-800-93-GREEN

www.greencentury.com

info@greencentury.com

INVESTMENT SUBADVISER (Balanced Fund)

Trillium Asset Management Corporation

711 Atlantic Avenue

Boston, MA 02111

INVESTMENT SUBADVISER (Equity Fund)

Mellon Capital Management Corporation

500 Grant Street Suite 4200

Pittsburgh, PA 15258

SUBADMINISTRATOR and DISTRIBUTOR

UMB Fund Services, Inc. (Subadministrator)

UMB Distribution Services, LLC (Distributor)

803 West Michigan Street, Suite A

Milwaukee, WI 53233

CUSTODIAN

State Street Bank and Trust Company

200 Clarendon Street

Boston, MA 02116

TRANSFER AGENT

Unified Fund Services, Inc.

2960 North Meridian Street, Suite 300

Indianapolis, IN 46208

INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

KPMG LLP

99 High Street

Boston, MA 02110

January 31, 2010

Balanced

Fund

An investment for your future.   Printed on recycled paper with soy-based ink. Equity
Fund

Item 2. Code of Ethics

Not applicable to semi-annual reports.

Item 3. Audit Committee Financial Expert

Not applicable to semi-annual reports.

Item 4. Principal Accountant Fees and Services

Not applicable to semi-annual reports.

Item 5. Audit Committee of Listed Registrants

Not applicable.

Item 6. Schedule of Investments

Included as part of the report to shareholders filed under item 1 of this Form N-CSR

Item 7. Disclosure of Proxy Voting Policies and Procedures for Closed-End Management Investment Companies

Not applicable.

Item 8. Portfolio Managers of Closed-End Management Investment Companies

Not applicable.

Item 9. Purchases of Equity Securities by Closed-End Management Investment Company and Affiliated Purchasers

Not applicable.

Item 10. Submission of Matters to a Vote of Security Holders

There were no material changes to the procedures by which shareholders may recommend nominees to the registrant’s Board of Trustees.

Item 11. Controls and Procedures

(a) Based on an evaluation of the disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940, as amended, the “Disclosure Controls”) as of a

date within 90 days of the filing date (the “Filing Date”) of this Form N-CSR (the “Report”), the registrant’s principal executive officer and principal financial officer have concluded that the Disclosure Controls are effectively designed to ensure that information that is required to be disclosed by the registrant in the Report is recorded, processed, summarized and reported within the time periods specified in the Securities and Exchange Commission’s rules and forms, including ensuring that information required to be disclosed in the Report is accumulated and communicated to the registrant’s management, including the registrant’s principal executive officer and principal financial officer, as appropriate to allow timely decisions regarding required disclosures.

(b) There were no changes in the registrant’s internal controls over financial reporting (as defined in Rule 30 a-3(d) under the Investment Company Act of 1940) that occurred during the fiscal period covered by this report that have materially affected, or are reasonably likely to materially affect, the registrant’s internal control over financial reporting.

Item 12. Exhibits

(a)(1)    Not applicable.

 (2) Certifications for each principal executive and principal financial officer as required by Rule 30a-2(a) under the Investment Company Act of 1940, as amended, (17 CFR 270.30a-2(a)) are filed herewith.

(b) Certifications required by Rule 30a-2 (b) under the Investment Company Act of 1940, as amended, (17 CFR 270.30a-2 (b)) are filed herewith.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

Green Century Funds

/s/ Kristina A. Curtis

Kristina A. Curtis

President and Principal Executive Officer

April 9, 2010

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

/s/ Kristina A. Curtis

Kristina A. Curtis

President and Principal Executive Officer

April 9, 2010

/s/ Kristina A. Curtis

Kristina A. Curtis

Treasurer and Principal Financial Officer

April 9, 2010