<SEC-DOCUMENT>0001144204-12-023563.txt : 20120424
<SEC-HEADER>0001144204-12-023563.hdr.sgml : 20120424
<ACCEPTANCE-DATETIME>20120424184755
ACCESSION NUMBER:		0001144204-12-023563
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20120423
FILED AS OF DATE:		20120424
DATE AS OF CHANGE:		20120424

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			HARMON JAMES N
		CENTRAL INDEX KEY:			0001547381

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-35521
		FILM NUMBER:		12777251

	MAIL ADDRESS:	
		STREET 1:		12870 INTERURBAN AVENUE SOUTH
		CITY:			SEATTLE
		STATE:			WA
		ZIP:			96168

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CLEARSIGN COMBUSTION CORP
		CENTRAL INDEX KEY:			0001434524
		STANDARD INDUSTRIAL CLASSIFICATION:	INDUSTRIAL INSTRUMENTS FOR MEASUREMENT, DISPLAY, AND CONTROL [3823]
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			WA

	BUSINESS ADDRESS:	
		STREET 1:		12870 INTERURBAN AVENUE SOUTH
		CITY:			SEATTLE
		STATE:			WA
		ZIP:			98168
		BUSINESS PHONE:		(206) 673-4848

	MAIL ADDRESS:	
		STREET 1:		12870 INTERURBAN AVENUE SOUTH
		CITY:			SEATTLE
		STATE:			WA
		ZIP:			98168
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>v310431_form3.xml
<DESCRIPTION>OWNERSHIP DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0205</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2012-04-23</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001434524</issuerCik>
        <issuerName>CLEARSIGN COMBUSTION CORP</issuerName>
        <issuerTradingSymbol>CLIR</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001547381</rptOwnerCik>
            <rptOwnerName>HARMON JAMES N</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>12870 INTERURBAN AVENUE SOUTH</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SEATTLE</rptOwnerCity>
            <rptOwnerState>WA</rptOwnerState>
            <rptOwnerZipCode>96168</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>CFO and Secretary</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>125000</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">50,000 shares of Mr. Harmon's common stock are subject to a repurchase option by the Company at $0.0001 per share in the event that Mr. Harmon terminates his employment, or upon other related circumstances, prior to June 30, 2012. 75,000 shares of Mr. Harmon's common stock are subject to a repurchase option by the Company at $0.0001 per share in the event that Mr. Harmon terminates his employment, or upon other related circumstances. As to the 75,000 shares, the repurchase right expires ratably and on a quarterly basis over the period October 1, 2012 to June 30, 2015. In the event of a change in control of the Company, the repurchase rights terminate.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ James N. Harmon</signatureName>
        <signatureDate>2012-04-24</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
