-----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,
 Gh/94Y2XCcskcTH+zas5aOVhQ55Z3Nm95iDpTOnnU53j6QXJO+Zp8owqJI4tfpUu
 80zfHRrGFKeycBXi9wDqBw==

<SEC-DOCUMENT>0001004440-04-000004.txt : 20040105
<SEC-HEADER>0001004440-04-000004.hdr.sgml : 20040105
<ACCEPTANCE-DATETIME>20040105165208
ACCESSION NUMBER:		0001004440-04-000004
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20040101
FILED AS OF DATE:		20040105

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CONSTELLATION ENERGY GROUP INC
		CENTRAL INDEX KEY:			0001004440
		STANDARD INDUSTRIAL CLASSIFICATION:	ELECTRIC SERVICES [4911]
		IRS NUMBER:				521964611
		STATE OF INCORPORATION:			MD
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		750 E PRATT ST
		CITY:			BALTIMORE
		STATE:			MD
		ZIP:			21202
		BUSINESS PHONE:		4107832800

	MAIL ADDRESS:	
		STREET 1:		750 E PRATT STREET
		CITY:			BALTIMORE
		STATE:			MD
		ZIP:			21202

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	CONSTELLATION ENERGY CORP
		DATE OF NAME CHANGE:	19951220

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	RH ACQUISITION CORP
		DATE OF NAME CHANGE:	19951205

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			LAMPTON NANCY
		CENTRAL INDEX KEY:			0001050739

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-25931
		FILM NUMBER:		04505812

	BUSINESS ADDRESS:	
		STREET 1:		C/O BALTIMORE GAS AND ELECTRIC COMPANY
		STREET 2:		P.O. BOX 1475
		CITY:			BALTIMORE
		STATE:			MD
		ZIP:			21203
		BUSINESS PHONE:		4102345575

	MAIL ADDRESS:	
		STREET 1:		C/O BALTIMORE GAS AND ELECTRIC COMPANY
		STREET 2:		P.O. BOX 1475
		CITY:			BALTIMORE
		STATE:			MD
		ZIP:			21203
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>

<ownershipDocument>

    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-01-01</periodOfReport>


    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001004440</issuerCik>
        <issuerName>CONSTELLATION ENERGY GROUP INC</issuerName>
        <issuerTradingSymbol>CEG</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001050739</rptOwnerCik>
            <rptOwnerName>LAMPTON NANCY</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>AMERICAN LIFE AND ACCIDENT INSURANCE CO.</rptOwnerStreet1>
            <rptOwnerStreet2>3 RIVERFRONT PLAZA</rptOwnerStreet2>
            <rptOwnerCity>LOUISVILLE</rptOwnerCity>
            <rptOwnerState>KY</rptOwnerState>
            <rptOwnerZipCode>40202</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>

        <derivativeTransaction>
            <securityTitle>
                <value>Phantom Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2004-01-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>393.8041</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>38.09</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>393.8041</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2762.9483</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>

    </derivativeTable>

    <footnotes>
        <footnote id="F1">This phantom stock is in the form of deferred stock units.</footnote>
        <footnote id="F2">The units are settled in cash upon the reporting person's termination of service as a director or earlier upon reaching age 70, if elected by the reporting person.</footnote>
        <footnote id="F3">Includes shares acquired through dividend reinvestment.</footnote>
    </footnotes>


    <ownerSignature>
        <signatureName>Constance F. Smith, Attorney-In-Fact</signatureName>
        <signatureDate>2004-01-05</signatureDate>
    </ownerSignature>

</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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