<SEC-DOCUMENT>0001415889-15-002047.txt : 20150615
<SEC-HEADER>0001415889-15-002047.hdr.sgml : 20150615
<ACCEPTANCE-DATETIME>20150615165904
ACCESSION NUMBER:		0001415889-15-002047
CONFORMED SUBMISSION TYPE:	4/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20150528
FILED AS OF DATE:		20150615
DATE AS OF CHANGE:		20150615

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MERCANTILE BANK CORP
		CENTRAL INDEX KEY:			0001042729
		STANDARD INDUSTRIAL CLASSIFICATION:	STATE COMMERCIAL BANKS [6022]
		IRS NUMBER:				383360865
		STATE OF INCORPORATION:			MI
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		310 LEONARD STREET NW
		CITY:			GRAND RAPIDS
		STATE:			MI
		ZIP:			49504
		BUSINESS PHONE:		616 406-3000

	MAIL ADDRESS:	
		STREET 1:		310 LEONARD STREET NW
		CITY:			GRAND RAPIDS
		STATE:			MI
		ZIP:			49504

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			GARDNER JEFF A
		CENTRAL INDEX KEY:			0001337974

	FILING VALUES:
		FORM TYPE:		4/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-26719
		FILM NUMBER:		15931770

	MAIL ADDRESS:	
		STREET 1:		C/O FIRSTBANK CORPORATION
		STREET 2:		311 WOODWORTH AVENUE
		CITY:			ALMA
		STATE:			MI
		ZIP:			48801
</SEC-HEADER>
<DOCUMENT>
<TYPE>4/A
<SEQUENCE>1
<FILENAME>form4a-06152015_010656.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2015-05-28</periodOfReport>

    <dateOfOriginalSubmission>2015-06-01</dateOfOriginalSubmission>

    <issuer>
        <issuerCik>0001042729</issuerCik>
        <issuerName>MERCANTILE BANK CORP</issuerName>
        <issuerTradingSymbol>MBWM</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001337974</rptOwnerCik>
            <rptOwnerName>GARDNER JEFF A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MERCANTILE BANK CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>310 LEONARD STREET</rptOwnerStreet2>
            <rptOwnerCity>GRAND RAPIDS</rptOwnerCity>
            <rptOwnerState>MI</rptOwnerState>
            <rptOwnerZipCode>49504</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>true</isDirector>
            <isOfficer>false</isOfficer>
            <isTenPercentOwner>false</isTenPercentOwner>
            <isOther>false</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2015-05-28</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>750</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>12784</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">This Amendment is filed solely to include shares acquired by the reporting person since his last report of common stock ownership by reinvesting cash dividends under the issuer's dividend reinvestment plan.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Bradley J. Wyatt, Attorney-in-Fact</signatureName>
        <signatureDate>2015-06-15</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
