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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,
 WgCChzFG2jxCOh9ck5GOTQ1BwE34G9rMYyTm9r7E61gqvrvAAb7JggTqct537Qum
 y72/fZZ+ZpsYMj6p/p4Vtw==

<SEC-DOCUMENT>0001289419-10-000345.txt : 20100805
<SEC-HEADER>0001289419-10-000345.hdr.sgml : 20100805
<ACCEPTANCE-DATETIME>20100805170617
ACCESSION NUMBER:		0001289419-10-000345
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20100805
FILED AS OF DATE:		20100805
DATE AS OF CHANGE:		20100805

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Chen Peng
		CENTRAL INDEX KEY:			0001371454

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-51280
		FILM NUMBER:		10995343

	MAIL ADDRESS:	
		STREET 1:		C/O MORNINGSTAR, INC.
		STREET 2:		225 W. WACKER DRIVE
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60606

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Morningstar, Inc.
		CENTRAL INDEX KEY:			0001289419
		STANDARD INDUSTRIAL CLASSIFICATION:	INVESTMENT ADVICE [6282]
		IRS NUMBER:				363297908
		STATE OF INCORPORATION:			IL
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		22 WEST WASHINGTON STREET
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60602
		BUSINESS PHONE:		(312) 696-6000

	MAIL ADDRESS:	
		STREET 1:		22 WEST WASHINGTON STREET
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60602
</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>2010-08-05</periodOfReport>

    <issuer>
        <issuerCik>0001289419</issuerCik>
        <issuerName>Morningstar, Inc.</issuerName>
        <issuerTradingSymbol>MORN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001371454</rptOwnerCik>
            <rptOwnerName>Chen Peng</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MORNINGSTAR, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>22 WEST WASHINGTON STREET</rptOwnerStreet2>
            <rptOwnerCity>CHICAGO</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60602</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Pres., Ibbotson Assoc.</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-08-05</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>45.34</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>17988</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The sales reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on June 1, 2010.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Heidi Miller, by power of attorney</signatureName>
        <signatureDate>2010-08-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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