UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the
Securities Exchange Act of 1934

Date of Report (Date of earliest event reported):  May 15, 2008

SOUTHERN MICHIGAN BANCORP, INC.
(Exact Name of Registrant as
Specified in Charter)

Michigan
(State or Other Jurisdiction
of Incorporation) 000-49722
(Commission
File Number) 38-2407501
(IRS Employer
Identification No.)

51 West Pearl Street
Coldwater, Michigan
(Address of Principal Executive Offices)
49036
(Zip Code)

Registrant's telephone number,
including area code:  (517) 279-5500

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the Registrant under any of the following provisions:

o Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425).

o Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12).

o Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)).

o Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)).

Item 7.01. Regulation FD Disclosure.

          On May 15, 2008, Southern Michigan Bancorp, Inc. mailed it's quarterly report to shareholders, which included previously disclosed results of operations and a letter to shareholders from the Chairman of the Board and Chief Executive Officer. The letter is attached to this report as Exhibit 99.1.

          The information in this report (including the letter to shareholders) is furnished pursuant to Item 7.01 and shall not be deemed to be "filed" for the purposes of the Securities Exchange Act of 1934, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, except as shall be expressly set forth by specific reference in such a filing.

Forward-Looking Statements

          This report and the letter to shareholders contains forward-looking statements that are based on management's beliefs, assumptions, current expectations, estimates and projections about the financial services industry, the economy, and Southern Michigan Bancorp, Inc. Forward-looking statements are identifiable by words or phrases such as that an event or trend "will enable" or "will be invaluable." These statements are not guarantees of future performance and involve certain risks, uncertainties and assumptions ("risk factors") that are difficult to predict with regard to timing, extent, likelihood and degree of occurrence. Therefore, actual results and outcomes may materially differ from what may be expressed or forecasted in such forward-looking statements.

          Risk factors include, but are not limited to, a failure by Southern Michigan Bancorp, Inc. to realize substantial or any reductions in operating costs beginning in 2009 as a result of the standardization of duplicative operating functions of Southern and FNB Financial; the risk factors described in "Item 1A - Risk Factors" of Southern Michigan Bancorp, Inc.'s Annual Report on Form 10-K for the year ended December 31, 2007; the timing and level of asset growth; changes in banking laws and regulations; changes in tax laws; changes in prices, levies and assessments; the impact of technological advances and issues; governmental and regulatory policy changes; opportunities for acquisitions and the effective completion of acquisitions and integration of acquired entities; the possibility that anticipated cost savings and revenue enhancements from acquisitions, restructurings, reorganizations and bank consolidations may not be realized at amounts projected, at all or within expected time frames; the local and global effects of the ongoing war on terrorism and other military actions, including actions in Iraq; and current uncertainties and fluctuations in the financial markets and stocks of financial services providers due to concerns about credit availability and concerns about the Michigan economy in particular. These and other factors are representative of the risk factors that may emerge and could cause a difference between an ultimate actual outcome and a preceding forward-looking statement.

          This section is intended to provide meaningful cautionary statements. This should not be construed as a complete list of all economic, competitive, governmental, technological, and other factors that could adversely affect our expected consolidated financial position, results of

operations or liquidity. Southern Michigan Bancorp, Inc. undertakes no obligation to update or revise any forward-looking statements to reflect developments that occur or information obtained after the date of this report.

Item 9.01.	Financial Statements and Exhibits.
	(d)	Exhibits:
	99.1	Letter to Shareholders.

SIGNATURES

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

Date:  May 15, 2008	SOUTHERN MICHIGAN BANCORP, INC.
	By	/s/ Danice L. Chartrand
		Danice L. Chartrand Senior Vice President, Chief Financial Officer, Secretary, and Treasurer

EXHIBIT INDEX

Exhibit Number	Document
99.1	Letter to Shareholders.