SCHEDULE 13G  
  
Amendment No.   
Sealed Air Corporation  
Common Stock  
Cusip # 81211K100  
 
 
Cusip # 81211K100  
Item 1:	Reporting Person - FMR Corp.  
Item 4:	Commonwealth of Massachusetts  
Item 5:	575,636  
Item 6:	None  
Item 7:	10,853,355  
Item 8:	None  
Item 9:	10,853,355  
Item 11:	12.80%  
Item 12:	HC   
  
  
 
 
Cusip # 81211K100  
Item 1:	Reporting Person - Edward C. Johnson 3d   
Item 4:	United States of America  
Item 5:	None  
Item 6:	None  
Item 7:	10,853,355  
Item 8:	None  
Item 9:	10,853,355  
Item 11:	12.80%  
Item 12:	IN   
  
 
 
Cusip # 81211K100  
Item 1:	Reporting Person - Abigail P. Johnson   
Item 4:	United States of America  
Item 5:	None  
Item 6:	None  
Item 7:	10,853,355  
Item 8:	None  
Item 9:	10,853,355  
Item 11:	12.80%  
Item 12:	IN   
  
 
 
SCHEDULE 13G - TO BE INCLUDED IN STATEMENTS  
FILED PURSUANT TO RULE 13d-1(b) or 13d-2(b)  
  
  
Item 1(a).	Name of Issuer:  
  
		Sealed Air Corporation  
  
Item 1(b).	Name of Issuer's Principal Executive Offices:  
  
		Park 80 East   
		Saddle Brook, NJ  07663  
  
Item 2(a).	Name of Person Filing:   
  
		FMR Corp.  
  
Item 2(b).	Address or Principal Business Office or, if None, Residence:  
  
		82 Devonshire Street, Boston, Massachusetts  02109  
  
Item 2(c).	Citizenship:  
  
		Not applicable  
  
Item 2(d).	Title of Class of Securities:  
  
		Common Stock  
  
Item 2(e).	CUSIP Number:    
  
		81211K100  
  
Item 3.	This statement is filed pursuant to Rule 13d-1(b) or 13d-2(b) and the  
person filing, FMR Corp., is a parent holding company in accordance  
with Section 240.13d-1(b)(ii)(G).  (Note:  See Item 7).  
  
Item 4.	Ownership  
  
	(a)	Amount Beneficially Owned: 
	10,853,355  
  
	(b)	Percent of Class: 
	12.80%  
  
	(c)	Number of shares as to which such person has:    
  
	(i)	sole power to vote or to direct the vote: 
	575,636  
  
	(ii)	shared power to vote or to direct the vote: 
	None  
  
	(iii)	sole power to dispose or to direct the disposition of: 
	10,853,355  
  
	(iv)	shared power to dispose or to direct the disposition of: 
	None  
  
  
 
 
Item 5.	Ownership of Five Percent or Less of a Class.  
  
	Not applicable.  
  
Item 6.	Ownership of More than Five Percent on Behalf of Another Person.  
  
	Various persons have the right to receive or the power to  
direct the receipt of dividends from, or the proceeds from the  
sale of, the common stock of Sealed Air Corporation.  No one  
person's interest in the common stock of Sealed Air Corporation  
is more than five percent of the total outstanding common  
stock.  
  
Item 7.	Identification and Classification of the Subsidiary Which Acquired  
the Security Being Reported on By the Parent Holding Company.  
  
	See attached Exhibit(s) A, B, and C.  
  
Item 8.	Identification and Classification of Members of the Group.  
  
	Not applicable, see attached Exhibit A.   
  
Item 9.	Notice of Dissolution of Group.  
  
	Not applicable.  
  
Item 10.	Certification.  
  
	By signing below I certify that, to the best of my knowledge  
and belief, the securities referred to above were acquired in  
the ordinary course of business and were not acquired for the  
purpose of and do not have the effect of changing or  
influencing the control of the issuer of such securities and  
were not acquired in connection with or as a participant in any  
transaction having such purpose or effect.  
  
  
Signature  
  
	After reasonable inquiry and to the best of my knowledge and  
belief, I certify that the information set forth in this  
Schedule 13G in connection with FMR Corp.'s beneficial  
ownership of the common stock of Sealed Air Corporation at July  
31, 1998 is true, complete and correct.   
  
  
	August 10, 1998	  
Date  
  
  
  
	/s/Eric D. Roiter  
Signature  
  
  
  
	Eric D. Roiter	  
Duly authorized under Power of  
Attorney  
dated December 30, 1997, by  
and on behalf  
of FMR Corp. and its direct  
and indirect  
subsidiaries  
  
  
 
 
SCHEDULE 13G - TO BE INCLUDED IN STATEMENTS  
FILED PURSUANT TO RULE 13d-1(b) or 13d-2(b)  
  
	Pursuant to the instructions in Item 7 of Schedule 13G, Fidelity  
Management & Research Company ("Fidelity"), 82 Devonshire Street, Boston,  
Massachusetts 02109, a wholly-owned subsidiary of FMR Corp. and an investment  
adviser registered under Section 203 of the Investment Advisers Act of 1940,  
is the beneficial owner of 10,053,443 shares or 11.86% of the common stock  
outstanding of Sealed Air Corporation ("the Company") as a result of acting as  
investment adviser to various investment companies registered under Section 8  
of the Investment Company Act of 1940.  The number of shares of common stock  
of Sealed Air Corporation owned by the investment companies at July 31, 1998  
included 1,494,089 shares of common stock resulting from the assumed  
conversion of 1,688,660 shares of the Sealed Air Ser A $2.0 Convertible  
Preferred Debenture (0.8846 shares of common stock for each share of the  
Sealed Air Ser A $2.0 Convertible Preferred Debenture).  
  
	Edward C. Johnson 3d, FMR Corp., through its control of Fidelity, and the  
funds each has sole power to dispose of the 10,053,443 shares owned by the  
Funds.  
  
	Neither FMR Corp. nor Edward C. Johnson 3d, Chairman of FMR Corp., has  
the sole power to vote or direct the voting of the 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' Boards of Trustees.  
  
	Fidelity Management Trust Company, 82 Devonshire Street, Boston,  
Massachusetts 02109, a wholly-owned subsidiary of FMR Corp. and a bank as  
defined in Section 3(a)(6) of the Securities Exchange Act of 1934, is the  
beneficial owner of 756,102 shares or 0.89% of the common stock outstanding of  
the Company as a result of its serving as investment manager of the  
institutional account(s).  The number of shares of common stock of Sealed Air  
Corporation owned by the institutional account(s) at July 31, 1998 included  
7,940 shares of common stock resulting from the assumed conversion of 8,976  
shares of the Sealed Air Ser A $2.0 Convertible Preferred Debenture described  
above.  
  
	Edward C. Johnson 3d and FMR Corp., through its control of Fidelity  
Management Trust Company, each has sole dispositive power over 756,102 shares  
and sole power to vote or to direct the voting of 531,826 shares, and no power  
to vote or to direct the voting of 224,276 shares of common stock owned by the  
institutional account(s) as reported above.  
  
	Members of the Edward C. Johnson 3d family and trusts for their benefit  
are the predominant owners of Class B shares of common stock of FMR Corp.,  
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.  Mr. Johnson 3d is Chairman of FMR Corp. and Abigail  
P. Johnson is a Director 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.    
  
	Fidelity International Limited, Pembroke Hall, 42 Crowlane, Hamilton,  
Bermuda, and various foreign-based subsidiaries provide investment advisory  
and management services to a number of non-U.S. investment companies (the  
"International Funds") and certain institutional investors.  Fidelity  
International Limited is the beneficial owner of 43,810 shares or 0.05% of the  
common stock outstanding of the Company.  Additional information with respect  
to the beneficial ownership of Fidelity International Limited is shown on  
Exhibit B, page 9.  
 
 
SCHEDULE 13G - TO BE INCLUDED IN STATEMENTS  
FILED PURSUANT TO RULE 13d-1(b) or 13d-2(b)  
  
  
	Pursuant to instructions in Item 7 of Schedule 13G, this Exhibit has been  
prepared  to identify Fidelity International Limited, Pembroke Hall, 42 Crow  
Lane, Hamilton, Bermuda, a Bermudan joint stock company incorporated for an  
unlimited duration by private act of the Bermuda Legislature (FIL) and an  
investment adviser to various investment companies (the "International Funds")  
and certain institutional investors, as a beneficial owner of the 43,810  
shares or 0.05% of the common stock outstanding of Sealed Air Corporation.  
  
	Prior to June 30, 1980, FIL was a majority-owned subsidiary of Fidelity  
Management & Research Company (Fidelity), a wholly-owned subsidiary of FMR  
Corp.  On that date, the shares of FIL held by Fidelity were distributed, as a  
dividend,  to the shareholders of FMR Corp.  FIL currently operates as an  
entity independent of FMR Corp. and Fidelity.  The International Funds and  
FIL's other clients, with the exception of Fidelity and an affiliated company  
of Fidelity, are non-U.S. entities.  
  
	A partnership controlled by Edward C. Johnson 3d and members of his  
family owns shares of FIL voting stock with the right to cast approximately  
39.89% of the total votes which may be cast by all holders of FIL voting  
stock.  Mr. Johnson 3d is Chairman of FMR Corp. and FIL.  FMR Corp. and FIL  
are separate and independent corporate entities, and their Boards of Directors  
are generally composed of different individuals.  Other than when one serves  
as a sub adviser to the other, their investment decisions are made  
independently, and their clients are generally different organizations.  
  
	FMR Corp. and FIL are of the view that they are not acting as a "group"  
for purposes of Section 13(d) under the Securities Exchange Act of 1934 (the  
"1934" Act) and that they are not otherwise required to attribute to each  
other the "beneficial ownership" of securities "beneficially owned" by the  
other corporation within the meaning of Rule 13d-3 promulgated under the 1934  
Act.  Therefore, they are of the view that the shares held by the other  
corporation need not be aggregated for purposes of Section 13(d). However, FMR  
Corp. is making this filing on a voluntary basis as if all of the shares are  
beneficially owned by FMR Corp. and FIL on a joint basis.  
  
	FIL may continue to have the International Funds or other accounts  
purchase shares subject to a number of factors, including, among others, the  
availability of shares for sale at what FIL considers to be reasonable prices  
and other investment opportunities that may be available to the International  
Funds.  
  
	FIL intends to review continuously the equity position of the  
International Funds and other accounts in the Company.  Depending upon its  
future evaluations of the business and 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, FIL 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.  
  
	FIL does not have a present plan or proposal which relates to or would  
result in (i) an extraordinary corporate transaction, such as a merger,  
reorganization, liquidation, or sale or 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.  
  
	FIL has the sole power to vote and the sole power to dispose of 43,810  
shares.    
 
 
SCHEDULE 13G - TO BE INCLUDED IN STATEMENTS  
FILED PURSUANT TO RULE 13d-1(b) or 13d-2(b)  
RULE 13d-1(f)(1)  AGREEMENT  
  
	The undersigned persons, on August 10, 1998, agree and consent to the  
joint filing on their behalf of this Schedule 13G in connection with their  
beneficial ownership of the common stock of Sealed Air Corporation at July 31,  
1998.  
	FMR Corp.  
	By	/s/Eric D. Roiter  
Eric D. Roiter 
Duly authorized under Power of  
Attorney  
dated December 30, 1997, by  
and on behalf  
of FMR Corp. and its direct  
and indirect subsidiaries  
	Edward C. Johnson 3d  
	By	/s/Eric D. Roiter  
Eric D. Roiter 
Duly authorized under Power of  
Attorney  
dated December 30, 1997, by  
and on behalf  
of Edward C. Johnson 3d  
	Abigail P. Johnson  
	By	/s/Eric D. Roiter  
Eric D. Roiter 
Duly authorized under Power of  
Attorney  
dated December 30, 1997, by  
and on behalf  
of Abigail P. Johnson  
	Fidelity Management & Research Company  
	By	/s/Eric D. Roiter  
Eric D. Roiter 
V.P. and General Counsel