KBR KBR Inc

CUSIP No. 48242W106 13G/A Page 2 of 5 Pages



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 (1) NAMES OF REPORTING PERSONS
 I.R.S. IDENTIFICATION NO.
 OF ABOVE PERSONS (ENTITIES ONLY)
 JANA PARTNERS LLC
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 (2) CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP **
 (a) [ ]
 (b) [ ]
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 (3) SEC USE ONLY
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 (4) CITIZENSHIP OR PLACE OF ORGANIZATION
 DELAWARE
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NUMBER OF (5) SOLE VOTING POWER
 8,385,417
SHARES --------------------------------------------------------------

BENEFICIALLY (6) SHARED VOTING POWER
 0
OWNED BY --------------------------------------------------------------

EACH (7) SOLE DISPOSITIVE POWER
 8,385,417
REPORTING --------------------------------------------------------------

PERSON WITH (8) SHARED DISPOSITIVE POWER
 0
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 (9) AGGREGATE AMOUNT BENEFICIALLY OWNED
 BY EACH REPORTING PERSON
 8,345,417
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 (10) CHECK BOX IF THE AGGREGATE AMOUNT
 IN ROW (9) EXCLUDES CERTAIN SHARES ** [ ]
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 (11) PERCENT OF CLASS REPRESENTED
 BY AMOUNT IN ROW (9)
 4.95%
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 (12) TYPE OF REPORTING PERSON **
 IA
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 ** SEE INSTRUCTIONS BEFORE FILLING OUT!

CUSIP No. 48242W106 13G/A Page 3 of 5 Pages


Item 1(a). Name of Issuer:
 KBR, Inc.

Item 1 (b). Address of Issuer's Principal Executive Offices:
 601 Jefferson Street, Suite 3400
 Houston, Texas 77002
 United States

Item 2 (a). Name of Person Filing:
 JANA Partners LLC

Item 2 (b). Address of Principal Business Office or, if None, Residence:
 200 Park Avenue, Suite 3300
 New York, New York 10166

Item 2 (c). Citizenship:

 This Statement is filed by JANA Partners LLC, a Delaware
 limited liability company. JANA Partners LLC is a private
 money management firm which holds the Common Stock of the
 Issuer in various accounts under its management and control.
 The principals of JANA Partners LLC, Barry Rosenstein and Gary
 Claar, are U.S. citizens.

Item 2 (d). Title of Class of Securities:

 Common Stock, par value $0.001 per share

Item 2 (e). CUSIP No:

 48242W106

Item 3. If this statement is filed pursuant to Sec. 240.13d-1(b)
 or 240.13d-2(b) or (c), check whether the person filing is a:

 (a) [ ] Broker or dealer registered under Section 15 of the Act,

 (b) [ ] Bank as defined in Section 3(a)(6) of the Act,

 (c) [ ] Insurance Company as defined in Section 3(a)(19) of the
 Act,

 (d) [ ] Investment Company registered under Section 8 of the
 Investment Company Act of 1940,

 (e) [ ] Investment Adviser in accordance with Rule
 13d-1(b)(1)(ii)(E),

 (f) [ ] Employee Benefit Plan or Endowment Fund in accordance
 with Rule 13d-1(b)(1)(ii)(F),

 (g) [ ] Parent Holding Company or control person in accordance
 with Rule 13d-1(b)(1)(ii)(G),

 (h) [ ] Savings Association as defined in Section 3(b) of the
 Federal Deposit Insurance Act,

CUSIP No. 48242W106 13G/A Page 4 of 5 Pages


 (i) [ ] Church Plan that is excluded from the definition of an
 investment company under Section 3(c)(14) of the Investment
 Company Act of 1940,

 (j) [ ] Group, in accordance with Rule 13d-1(b)(1)(ii)(J).


Item 4. Ownership

(a) Amount beneficially owned: 8,385,417
(b) Percent of Class: 4.95%
(c) Number of shares as to which JANA Partners LLC has:
 (i) Sole power to vote or to direct the vote: 8,385,417
 (ii) Shared power to vote or to direct the vote: 0
 (iii) Sole power to dispose or to direct the disposition: 8,385,417
 (iv) Shared power to dispose or to direct the disposition of: 0

Item 5. Ownership of Five Percent or Less of a Class.

 If this statement is being filed to report the fact that as of the
 date hereof the reporting person has ceased to be the beneficial owner
 of more than 5 percent of the class of securities, check the following
 [ ].

Item 6. Ownership of More than Five Percent on Behalf of Another Person.
 Not Applicable.

Item 7. Identification and Classification of the Subsidiary Which Acquired
 the Security Reported on the Parent Holding Company.
 Not Applicable.

Item 8. Identification and Classification of Members of the Group.
 Not Applicable.

Item 9. Notice of Dissolution of Group.
 Not Applicable.

CUSIP No. 48242W106 13G/A Page 5 of 5 Pages


Item 10. Certification.

 The Reporting Person hereby makes the following certification:

 By signing below we each certify that, to the best of our
knowledge and belief, the securities referred to above were not acquired and are
not being held for the purpose of or with the effect of changing or influencing
the control of the issuer of such securities and were not acquired and are not
held in connection with or as a participant in any transaction having that
purpose or effect.

 SIGNATURE

After reasonable inquiry and to the best of our knowledge and belief, we each
certify that the information set forth in this statement is true, complete, and
correct.


DATED: February 14, 2008




 JANA PARTNERS LLC


 By: /s/ Barry Rosenstein
 -------------------------------------
 Barry Rosenstein
 Managing Partner


 By: /s/ Gary Claar
 -------------------------------------
 Gary Claar
 General Partner