-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 H8DogO7s1NJgfjDdXNNN81FrIrLd/pwD+I2/hyMjMkqQYAkVs7dBcjzTdpCOgxOi
 YUsYkQiSBrbTszbMEnjrOQ==

<SEC-DOCUMENT>0000790070-10-000164.txt : 20100805
<SEC-HEADER>0000790070-10-000164.hdr.sgml : 20100805
<ACCEPTANCE-DATETIME>20100805161245
ACCESSION NUMBER:		0000790070-10-000164
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20100803
FILED AS OF DATE:		20100805
DATE AS OF CHANGE:		20100805

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			LINK MARK A
		CENTRAL INDEX KEY:			0001189186

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-09853
		FILM NUMBER:		10994614

	MAIL ADDRESS:	
		STREET 1:		EMC CORPORATION
		STREET 2:		176 SOUTH STREET
		CITY:			HOPKINTON
		STATE:			MA
		ZIP:			01748

	FORMER NAME:	
		FORMER CONFORMED NAME:	LINK MARK
		DATE OF NAME CHANGE:	20020913

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			EMC CORP
		CENTRAL INDEX KEY:			0000790070
		STANDARD INDUSTRIAL CLASSIFICATION:	COMPUTER STORAGE DEVICES [3572]
		IRS NUMBER:				042680009
		STATE OF INCORPORATION:			MA
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		176 SOUTH STREET
		CITY:			HOPKINTON
		STATE:			MA
		ZIP:			01748-9103
		BUSINESS PHONE:		5082937208

	MAIL ADDRESS:	
		STREET 1:		176 SOUTH STREET
		CITY:			HOPKINTON
		STATE:			MA
		ZIP:			01748-9103
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-08-03</periodOfReport>

    <issuer>
        <issuerCik>0000790070</issuerCik>
        <issuerName>EMC CORP</issuerName>
        <issuerTradingSymbol>EMC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001189186</rptOwnerCik>
            <rptOwnerName>LINK MARK A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>EMC CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>176 SOUTH STREET</rptOwnerStreet2>
            <rptOwnerCity>HOPKINTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>01748</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>SVP&amp; Chief Accounting Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-08-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>13679</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>90292</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-08-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>20518</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>110810</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Shares of restricted stock granted under the Amended and Restated EMC Corporation 2003 Stock Plan, which are subject to forfeiture upon certain events.  These shares will vest ratably over four years beginning one year from the date of grant.</footnote>
        <footnote id="F2">Shares of restricted stock granted under the Amended and Restated EMC Corporation 2003 Stock Plan, which shares are subject to certain restrictions on transfer and are subject to forfeiture upon certain events.  The restrictions on transfer and forfeiture with respect to the shares lapse on the fifth anniversary of the date of grant, but such restrictions may lapse ratably over three years if certain performance targets approved by the Board of Directors are met.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/Barbara E. Coluci, Attorney In Fact</signatureName>
        <signatureDate>2010-08-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----