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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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<SEC-DOCUMENT>0001179110-03-013368.txt : 20031223
<SEC-HEADER>0001179110-03-013368.hdr.sgml : 20031223
<ACCEPTANCE-DATETIME>20031223184347
ACCESSION NUMBER:		0001179110-03-013368
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20031222
FILED AS OF DATE:		20031223

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			HARTMAN RICK S
		CENTRAL INDEX KEY:			0001256235

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-12422
		FILM NUMBER:		031072343

	MAIL ADDRESS:	
		STREET 1:		18 WOODVIEW LANE
		CITY:			IVERNESS
		STATE:			IL
		ZIP:			60067

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MAINSOURCE FINANCIAL GROUP
		CENTRAL INDEX KEY:			0000720002
		STANDARD INDUSTRIAL CLASSIFICATION:	STATE COMMERCIAL BANKS [6022]
		IRS NUMBER:				351562245
		STATE OF INCORPORATION:			IN
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		201 N BROADWAY
		STREET 2:		PO BOX 87
		CITY:			GREENSBURG
		STATE:			IN
		ZIP:			47240
		BUSINESS PHONE:		8126630157

	MAIL ADDRESS:	
		STREET 1:		201 NORTH BROADWAY
		STREET 2:		P O BOX 87
		CITY:			GREENSBURG
		STATE:			IN
		ZIP:			47240

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	INDIANA UNITED BANCORP
		DATE OF NAME CHANGE:	19920703
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 4 -
<TEXT>
<XML>
<ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>
<periodOfReport>2003-12-22</periodOfReport>
<notSubjectToSection16>0</notSubjectToSection16>
    <issuer>
        <issuerCik>0000720002</issuerCik>
        <issuerName>MAINSOURCE FINANCIAL GROUP</issuerName>
        <issuerTradingSymbol>msfg</issuerTradingSymbol>
</issuer>
<reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001256235</rptOwnerCik>
            <rptOwnerName>HARTMAN RICK S</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>18 WOODVIEW LANE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>INVERNESS</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60067</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>1</isDirector>
<isOfficer>0</isOfficer>
<isTenPercentOwner>0</isTenPercentOwner>
<isOther>0</isOther>
<officerTitle></officerTitle>
<otherText></otherText>
</reportingOwnerRelationship>
</reportingOwner>
<nonDerivativeTable><nonDerivativeTransaction><securityTitle><value>Common</value>
</securityTitle>
<transactionDate><value>2003-12-22</value>
</transactionDate>
<transactionCoding><transactionFormType>4</transactionFormType>
<transactionCode>G</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
</transactionCoding>
<transactionAmounts><transactionShares><value>330</value>
</transactionShares>
<transactionPricePerShare><value>0</value>
</transactionPricePerShare>
<transactionAcquiredDisposedCode><value>A</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<postTransactionAmounts><sharesOwnedFollowingTransaction><value>52347</value>
<footnoteId id="F1"></footnoteId>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature><directOrIndirectOwnership><value>I</value>
</directOrIndirectOwnership>
<natureOfOwnership><value>FBO Children</value>
</natureOfOwnership>
</ownershipNature>
</nonDerivativeTransaction>
</nonDerivativeTable>
<derivativeTable></derivativeTable>
<footnotes><footnote id="F1">These totals include shares that were acquired through a 5% stock dividend issued by the company on January 17, 2003.  Summary of ownership:  31,780 Self; 5,458 Spouse; 7,572 Self/IRA; 1,753 Spouse/IRA; 5,784 FBO Children.  Total ownership 52,347.</footnote>
</footnotes>
<ownerSignature><signatureName>Rick S. Hartman</signatureName>
<signatureDate>2003-12-23</signatureDate>
</ownerSignature>
</ownershipDocument>

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