SCHEDULE 13D  
  
Amendment No. 21  
Quantum Corporation  
Common Stock   
Cusip # 747906105  
Filing Fee: No  
 
 
Cusip # 747906105  
Item 1:	Reporting Person - FMR Corp. - (Tax ID:  04-2507163)  
Item 4:	PF  
Item 6:	Commonwealth of Massachusetts  
Item 7:	None  
Item 8:	None  
Item 9:	4,246,600  
Item 10:	None  
Item 11:	4,246,600  
Item 13:	8.22%  
Item 14:	HC  
 
 
PREAMBLE  
  
	The filing of this Schedule 13D is not, and should not be  
deemed to be, an admission that such Schedule 13D is required to  
be filed.  See the discussion under Item 2.  
  
Item 1.	Security and Issuer.  
  
	This statement relates to shares of the Common Stock, $0.01  
par value (the "Shares") of Quantum Corporation, a Delaware  
corporation (the "Company").  The principal executive offices of  
the Company are located at 500 McCarthy Boulevard, Milpitas, CA  
95035.  
  
Item 2.	Identity and Background.  
  
	Item 2 is amended as follows:  
  
	This statement is being filed by FMR Corp., a Massachusetts  
Corporation ("FMR").  FMR is a holding company one of whose  
principal assets is the capital stock of a wholly-owned  
subsidiary, Fidelity Management & Research Company ("Fidelity"),  
which is also a Massachusetts corporation.  Fidelity is an  
investment advisor which is registered under Section 203 of the  
Investment Advisors Act of 1940 and which provides investment  
advisory services to more than 30 investment companies which are  
registered under Section 8 of the Investment Company Act of 1940  
and serves as investment advisor to certain other funds which are  
generally offered to limited groups of investors (the "Fidelity  
Funds").  Fidelity Management Trust Company ("FMTC"), a wholly- 
owned subsidiary of FMR Corp. and a bank as defined in Section  
3(a)(6) of the Securities Exchange Act of 1934, serves as trustee  
or managing agent for various private investment accounts,  
primarily employee benefit plans and serves as investment adviser  
to certain other funds which are generally offered to limited  
groups of investors (the "Accounts").  Various directly or  
indirectly held subsidiaries of FMR are also engaged in  
investment management, venture capital asset management,  
securities brokerage, transfer and shareholder servicing and real  
estate development.  The principal offices of FMR, Fidelity, and  
FMTC are located at 82 Devonshire Street, Boston, Massachusetts  
02109.  
  
 	Members of the Edward C. Johnson 3d family are the  
predominant owners of Class B shares of common stock representing  
approximately 49% of the voting power of FMR Corp.  Mr. Johnson  
3d owns 12.0% and Abigail Johnson owns 24.5% of the aggregate  
outstanding voting stock of FMR Corp.  The Johnson family group  
and all other Class B shareholders have entered into a  
shareholders' voting agreement under which all Class B shares  
will be voted in accordance with the majority vote of Class B  
shares.  Accordingly, through their ownership of voting common  
stock and the execution of the shareholders' voting agreement,  
members of the Johnson family may be deemed, under the Investment  
Company Act of 1940, to form a controlling group with respect to  
FMR Corp.Mr. Johnson 3d is Chairman of FMR Corp.  The business  
address and principal occupation of Mr. Johnson 3d is set forth  
in Schedule A hereto.  
  
	The Shares to which this statement relates are owned  
directly by three of the Fidelity Funds, and one of the Accounts.   
  
	The name, residence or business address, principal  
occupation or employment and citizenship of each of the executive  
officers and directors of FMR are set forth in Schedule A hereto.  
  
	Within the past five years, none of the persons named in  
this Item 2 or listed on Schedule A has been convicted in any  
criminal proceeding (excluding traffic violations or similar  
misdemeanors) or has been a party to any civil proceeding and as  
a result thereof was or is subject to any judgment, decree or  
final order enjoining future violations of, or prohibiting or  
mandating activities subject to federal or state securities laws  
or finding any violations with respect to such laws.  
  
  
  
Item 3.	Source and Amount of Funds or Other Consideration.  
  
	Item 3 is amended as follows:  
  
	The Fidelity Funds which own or owned Shares purchased in  
the aggregate 24,784,525 Shares for cash in the amount of  
approximately $367,995,758, including brokerage commissions.  The  
Fidelity Funds used their own assets in making such purchase and  
no part of the purchase price is represented by borrowed funds.   
Proceeds from 20,573,625 Shares sold aggregated approximately  
$321,121,595.  The attached Schedule B sets forth Shares  
purchased and/or sold since July 15, 1995.  
  
	The Accounts of FMTC which own or owned Shares purchased in  
the aggregate 1,009,895 Shares for cash in the amount of  
approximately $17,563,998, including brokerage commissions.  The  
Accounts used their own assets in making such purchase and no  
part of the purchase price is represented by borrowed funds.   
Proceeds from 983,011 Shares sold aggregated approximately  
$14,903,159.  The attached Schedule B sets forth Shares purchased  
and/or sold since July 15, 1995.  
  
Item 4.	Purpose of Transaction.  
  
	Item 4 is amended as follows:  
  
	The purpose of Fidelity and FMTC in having the Fidelity  
Funds and the Accounts purchase Shares is to acquire an equity  
interest in the Company in pursuit of specified investment  
objectives established by the Board of Trustees of the Fidelity  
Funds and by the investors in the Accounts.  
  
	Fidelity and FMTC, respectively, may continue to have the  
Fidelity Funds and the Accounts purchase Shares subject to a  
number of factors, including, among others, the availability of  
Shares of sale at what they consider to be reasonable prices and  
other investment opportunities that may be available to the  
Fidelity Funds and Accounts.  
  
	Fidelity and FMTC, respectively, intend to review  
continuously the equity position of the Fidelity Funds and  
Accounts in the Company.  Depending upon future evaluations of  
the business prospects of the Company and upon other  
developments, including, but not limited to, general economic and  
business conditions and money market and stock market conditions,  
Fidelity may determine to cease making additional purchases of  
Shares or to increase or decrease the equity interest in the  
Company by acquiring additional Shares, or by disposing of all or  
a portion of the Shares.  
  
	Neither Fidelity nor FMTC has any present plan or proposal  
which relates to or would result in (i) an extraordinary  
corporate transaction, such as a merger, reorganization,  
liquidation, or sale of transfer of a material amount of assets  
involving the Company or any of its subsidiaries, (ii) any change  
in the Company's present Board of Directors or management, (iii)  
any material changes in the Company's present capitalization or  
dividend policy or any other material change in the Company's  
business or corporate structure, (iv) any change in the Company's  
charter or by-laws, or (v) the Company's common stock becoming  
eligible for termination of its registration pursuant to Section  
12(g)(4) of the 1934 Act.  
  
Item 5.	Interest in Securities of Issuer.  
  
	Item 5 is amended as follows:  
  
	FMR, Fidelity, and FMTC, beneficially own all 4,246,600  
Shares.  
  
	(a)	FMR beneficially owns, through Fidelity, as investment  
advisor to the Fidelity Funds, 4,210,900 Shares, or approximately  
8.15% of the outstanding Shares of the Company, and through FMTC,  
the managing agent for the Accounts, 35,700 Shares, or  
approximately 0.07% of the outstanding Shares of the Company.  
Neither FMR, Fidelity, FMTC, nor any of its affiliates nor, to  
the best knowledge of FMR, any of the persons name in Schedule A  
hereto, beneficially owns any other Shares.  The combined  
holdings of FMR, Fidelity, and FMTC, are 4,246,600 Shares, or  
approximately 8.22% of the outstanding Shares of the Company.  
  
	(b)	FMR, through its control of Fidelity, investment  
advisor to the Fidelity Funds, and the Funds each has sole power  
to dispose of the Shares.  Neither FMR nor Mr. Johnson has the  
sole power to vote or direct the voting of the 4,210,900 Shares  
owned directly by the Fidelity Funds, which power resides with  
the Funds' Boards of Trustees.  Fidelity carries out the voting  
of the Shares under written guidelines established by the Funds'  
Board of Trustees.  FMR, through its control of FMTC, investment  
manager to the Accounts, and the Accounts each has sole  
dispositive power over 35,700 Shares and sole power to vote or to  
direct the voting of 0 Shares, and no power to vote or to direct  
the voting of 35,700 Shares owned by the Accounts.    
  
	(c)	Except as set forth in Schedule B, neither FMR, or any  
of its affiliates, nor, to the best knowledge of FMR, any of the  
persons named in Schedule A hereto has effected any transaction  
in Shares during the past sixty (60) days.  
  
Item 6.	Contract, Arrangements, Understandings or Relationships  
With Respect to Securities of the Issuer.  
  
	Neither FMR nor any of its affiliates nor, to the best  
knowledge of FMR, any of the persons named in Schedule A hereto  
has any joint venture, finder's fee, or other contract or  
arrangement with any person with respect to any securities of the  
Company.  
  
Item 7.	Material to be Filed as Exhibits.  
  
	Not Applicable.  
  
	This statement speaks as of its date, and no inference  
should be drawn that no change has occurred in the facts set  
forth herein after the date hereof.  
  
Signature  
  
	After reasonable inquiry and to the best of my knowledge and  
belief, I certify that the information set forth in this  
statement is true, complete and correct.  
  
						FMR Corp.  
  
  
  
DATE:	September 15, 1995	By:	/s/Arthur  
Loring			  
	Arthur Loring  
	Vice President-Legal  
  
  
 
 
SCHEDULE A  
  
	The name and present principal occupation or employment of  
each executive officer and director of FMR Corp. are set forth  
below.  The business address of each person is 82 Devonshire  
Street, Boston, Massachusetts 02109, and the address of the  
corporation or organization in which such employment is conducted  
is the same as his business address.  All of the persons listed  
below are U.S. citizens.  
  
POSITION WITH  
									PRINCIPAL  
NAME	FMR CORP.	OCCUPATION  
  
Edward C. Johnson 3d	President, 
	Chairman of the  
Director, CEO	Board and CEO, FMR  
Chairman &  
Mng. Director  
  
J. Gary Burkhead	Director	President-Fidelity  
  
Caleb Loring, Jr.	Director,	Director, FMR  
	Mng. Director  
  
James C. Curvey	Director, 	Sr. V.P., FMR  
	Sr. V.P.  
  
William L. Byrnes	Vice Chairman	Vice Chairman, FIL  
Director & Mng.  
Director  
  
Robert C. Pozen	Sr. V.P. & Gen'l	Sr. V.P. & Gen'l  
	Counsel	Counsel, FMR  
  
Mark Peterson	Exec.	Exec.  
V.P.-Management	V.P.-Management  
Resources	Resources, FMR  
  
Denis McCarthy	Sr. Vice Pres. - 	Vice Pres., Chief  
Chief Financial	Financial Officer,  
Officer	FMR  
  
  
  
	  
 
 
SCHEDULE B  
  
  
Quantum Corporation  
  
Two Fidelity Fund(s) purchased common stock since July 15, 1995  
at the dates and at the prices set forth below.  The transactions  
were made for cash in open market transactions or with other  
investment companies with the same or an affiliated investment  
advisor.  
  
	DATE	SHARES	PRICE  
  
	07-18-95	87,600	$23.63  
	07-25-95	22,000	24.50  
	08-01-95	16,800	24.88  
	08-30-95	23,900	24.19  
	08-30-95	119,500	24.38		  
  
  
 
 
SCHEDULE B  
  
  
Quantum Corporation  
  
Four Fidelity Fund(s) sold common stock since July 15, 1995 at  
the dates and at the prices set forth below.  The transactions  
were made for cash in open market transactions or with other  
investment companies with the same or an affiliated investment  
advisor.  
  
	DATE	SHARES	PRICE  
  
	07-18-95	87,600	$23.63  
	09-07-95	50,000	25.25  
	09-08-95	25,000	25.50  
	09-11-95	100,000	23.50  
	09-12-95	297,700	22.08  
	09-13-95	1,404,700	22.19  
	  
  
 
 
SCHEDULE B  
  
  
Quantum Corporation  
  
Four Account(s) purchased common stock since July 15, 1995 at the  
dates and at the prices set forth below.  The transactions were  
made for cash in open market transactions or with other  
investment companies with the same or an affiliated investment  
advisor.  
  
	DATE	SHARES	PRICE  
  
	07-25-95	5,000	$24.50  
	08-01-95	800	24.88  
	08-30-95	1,100	24.19  
	08-30-95	5,500	24.38  
		  
  
 
 
SCHEDULE B  
  
  
Quantum Corporation  
  
Two Account(s) sold common stock since July 15, 1995 at the dates  
and at the prices set forth below.  The transactions were made  
for cash in open market transactions or with other investment  
companies with the same or an affiliated investment advisor.  
  
	DATE	SHARES	PRICE  
  
	09-12-95	2,300	$22.08  
	09-13-95	19,200	22.51  
  
 
 
SCHEDULE B  
  
  
Quantum Corporation  
  
One Account(s) sold Shares of the Convertible Subordinate  
Debenture since July 15, 1995 at the dates and at the prices set  
forth below.  The transactions were made for cash in open market  
transactions or with other investment companies with the same or  
an affiliated investment advisor.  
  
	DATE	SHARES	PRICE  
  
	07-26-95	680,000	$136.93