-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 A0PInPYAz7kIv4Zt5Z3KPN16h/xEjhw0EPAiBhquBtQl3j+19E97vM4T5qaaWAbw
 boUI/zCYpGe16Wiz6akjcg==

<SEC-DOCUMENT>0000205716-03-000155.txt : 20030716
<SEC-HEADER>0000205716-03-000155.hdr.sgml : 20030716
<ACCEPTANCE-DATETIME>20030716145719
ACCESSION NUMBER:		0000205716-03-000155
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030714
FILED AS OF DATE:		20030716

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			GRAHAM JOHN G
		CENTRAL INDEX KEY:			0001063789

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-05324
		FILM NUMBER:		03789150

	BUSINESS ADDRESS:	
		STREET 1:		VERNON ARCHIBALD C/O KELLEY DRYE & WARRE
		STREET 2:		TWO STAMFORD PLAZA 281 TRESSER BLVD
		CITY:			STAMFORD
		STATE:			CT
		ZIP:			06901

	MAIL ADDRESS:	
		STREET 1:		VERNON ARCHIBALD C/O KELLEY DRYE & WARRE
		STREET 2:		TWO STAMFORD PLAZA 281 TRESSER BLVD
		CITY:			STAMFORD
		STATE:			CT
		ZIP:			06901

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			NORTHEAST UTILITIES SYSTEM
		CENTRAL INDEX KEY:			0000072741
		STANDARD INDUSTRIAL CLASSIFICATION:	ELECTRIC SERVICES [4911]
		IRS NUMBER:				042147929
		STATE OF INCORPORATION:			MA
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		174 BRUSH HILL AVE
		CITY:			WEST SPRINGFIELD
		STATE:			MA
		ZIP:			01090-0010
		BUSINESS PHONE:		4137855871

	MAIL ADDRESS:	
		STREET 1:		107 SELDEN ST
		CITY:			BERLIN
		STATE:			CT
		ZIP:			06037-1616
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>

<ownershipDocument>

    <documentType>4</documentType>

    <periodOfReport>2003-07-14</periodOfReport>


    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000072741</issuerCik>
        <issuerName>NORTHEAST UTILITIES SYSTEM</issuerName>
        <issuerTradingSymbol>NU</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001063789</rptOwnerCik>
            <rptOwnerName>GRAHAM JOHN G</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Trustee</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeSecurity>
        <securityTitle>
            <value>Common Shares, $5 par value</value>
        </securityTitle>
        <transactionDate>
            <value>2003-07-14</value>
        </transactionDate>
        <transactionCoding>
            <transactionFormType>4</transactionFormType>
            <transactionCode>A</transactionCode>
            <equitySwapInvolved>0</equitySwapInvolved>
        </transactionCoding>
        <transactionTimeliness>
            <value></value>
        </transactionTimeliness>
        <transactionAmounts>
            <transactionShares>
                <value>46</value>
                <footnoteId id="F1"/>
            </transactionShares>
            <transactionValue>
                <value>16.27</value>
            </transactionValue>
            <transactionAcquiredDisposedCode>
                <value>A</value>
            </transactionAcquiredDisposedCode>
        </transactionAmounts>
        <postTransactionAmounts>
            <sharesOwnedFollowingTransaction>
                <value>4711</value>
                <footnoteId id="F2"/>
            </sharesOwnedFollowingTransaction>
        </postTransactionAmounts>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>D</value>
            </directOrIndirectOwnership>
        </ownershipNature>
    </nonDerivativeSecurity>

    <nonDerivativeSecurity>
        <securityTitle>
            <value>Common Shares, $5 par value</value>
        </securityTitle>
        <transactionDate>
            <value>2003-07-15</value>
        </transactionDate>
        <transactionCoding>
            <transactionFormType>4</transactionFormType>
            <transactionCode>A</transactionCode>
            <equitySwapInvolved>0</equitySwapInvolved>
        </transactionCoding>
        <transactionTimeliness>
            <value></value>
        </transactionTimeliness>
        <transactionAmounts>
            <transactionShares>
                <value>78</value>
                <footnoteId id="F1"/>
            </transactionShares>
            <transactionValue>
                <value>16.09</value>
            </transactionValue>
            <transactionAcquiredDisposedCode>
                <value>A</value>
            </transactionAcquiredDisposedCode>
        </transactionAmounts>
        <postTransactionAmounts>
            <sharesOwnedFollowingTransaction>
                <value>4789</value>
                <footnoteId id="F3"/>
            </sharesOwnedFollowingTransaction>
        </postTransactionAmounts>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>D</value>
            </directOrIndirectOwnership>
        </ownershipNature>
    </nonDerivativeSecurity>

    <footnotes>
        <footnote id="F1">Shares receipt of which has been deferred.</footnote>
        <footnote id="F2">Includes shares receipt of which has been deferred.  Includes deferred reinvested dividends.  This is a running tally as per Q&amp;A 3 of the Division of Corporate Finance's &quot;Section 16 Electronic Reporting Frequently Asked Questions&quot; dated March 13, 2003.</footnote>
        <footnote id="F3">Includes shares receipt of which has been deferred.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>John G. Graham, By: O. Kay Comendul/POA</signatureName>
        <signatureDate>2003-07-16</signatureDate>
    </ownerSignature>

</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----