-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 Wla2n5tUCeFCo+oURGxkfz8u+e9zg87DD89Vh2D5ZlfX5abaqdXoR0sPB7Ep9US1
 Kax5gyUD+BEA7IKITN3A1w==

<SEC-DOCUMENT>0001109357-08-000238.txt : 20080829
<SEC-HEADER>0001109357-08-000238.hdr.sgml : 20080829
<ACCEPTANCE-DATETIME>20080829103002
ACCESSION NUMBER:		0001109357-08-000238
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080827
FILED AS OF DATE:		20080829
DATE AS OF CHANGE:		20080829

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			O'Brien Denis P.
		CENTRAL INDEX KEY:			0001411723

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-16169
		FILM NUMBER:		081047442

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		(312) 394-7398

	MAIL ADDRESS:	
		STREET 1:		10 SOUTH DEARBORN STREET
		STREET 2:		54TH FLOOR
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60603

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			EXELON CORP
		CENTRAL INDEX KEY:			0001109357
		STANDARD INDUSTRIAL CLASSIFICATION:	ELECTRIC & OTHER SERVICES COMBINED [4931]
		IRS NUMBER:				232990190
		STATE OF INCORPORATION:			PA
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		PO BOX 805398
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60680-5398
		BUSINESS PHONE:		3123947399

	MAIL ADDRESS:	
		STREET 1:		PO BOX 805398
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60680-5398
</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>2008-08-27</periodOfReport>

    <issuer>
        <issuerCik>0001109357</issuerCik>
        <issuerName>EXELON CORP</issuerName>
        <issuerTradingSymbol>EXC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001411723</rptOwnerCik>
            <rptOwnerName>O'Brien Denis P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>10 SOUTH DEARBORN STREET</rptOwnerStreet1>
            <rptOwnerStreet2>54TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>CHICAGO</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60603</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Executive Vice President</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Deferred Comp. Phantom Shares</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2008-08-27</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>13</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>77.36</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>13</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2293</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Phantom shares held in a multi-fund deferred compensation plan to be settled for cash upon the reporting person's termination of employment for any reason on a 1:1 basis. Shares are acquired through regular periodic contributions, company matching contributions, and the automatic reinvestment of dividends.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Lawrence C. Bachman,  Attorney in Fact for Denis P. O'Brien</signatureName>
        <signatureDate>2008-08-29</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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