-----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,
 R39oEGlyGFs2WamV6G13tswXeXjPiap3/ahGdcvyvPLf7FvUg25JEA13avP0XfbG
 YTbynA0P+T2xuFgSfza4+Q==

<SEC-DOCUMENT>0001326430-08-000004.txt : 20080409
<SEC-HEADER>0001326430-08-000004.hdr.sgml : 20080409
<ACCEPTANCE-DATETIME>20080409095353
ACCESSION NUMBER:		0001326430-08-000004
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080407
FILED AS OF DATE:		20080409
DATE AS OF CHANGE:		20080409

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			HORIZON BANCORPORATION INC
		CENTRAL INDEX KEY:			0001074458
		STANDARD INDUSTRIAL CLASSIFICATION:	NATIONAL COMMERCIAL BANKS [6021]
		IRS NUMBER:				650840565
		STATE OF INCORPORATION:			FL
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		900 53RD AVENUE EAST
		CITY:			BRADENTON
		STATE:			FL
		ZIP:			34203
		BUSINESS PHONE:		9417532265

	MAIL ADDRESS:	
		STREET 1:		900 53RD AVENUE EAST
		CITY:			BRADENTON
		STATE:			FL
		ZIP:			34203

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Chapin Jeffrey S
		CENTRAL INDEX KEY:			0001383051

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-50748
		FILM NUMBER:		08746707

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		941-748-6747

	MAIL ADDRESS:	
		STREET 1:		15107 3RD DRIVE EAST
		CITY:			BRADENTON
		STATE:			FL
		ZIP:			34212
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-04-07</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001074458</issuerCik>
        <issuerName>HORIZON BANCORPORATION INC</issuerName>
        <issuerTradingSymbol>HZNB</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001383051</rptOwnerCik>
            <rptOwnerName>Chapin Jeffrey S</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>15107 3RD DRIVE EAST</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BRADENTON</rptOwnerCity>
            <rptOwnerState>FL</rptOwnerState>
            <rptOwnerZipCode>34212</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Senior Vice President</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2008-04-07</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>235</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>10.65</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>235</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2008-04-07</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>235</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>10.65</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1042</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>In Wife's IRA</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <ownerSignature>
        <signatureName>Jeffrey S. Chapin</signatureName>
        <signatureDate>2008-04-09</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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