Ownership Submission
FORM 3
 UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
  Liu Michael K
 2. Date of Event Requiring Statement (Month/Day/Year)
04/01/2007		 3. Issuer Name and Ticker or Trading Symbol
KNIGHT TRANSPORTATION INC [KNX]
(Last)
(First)
(Middle)
5601 WEST BUCKEYE ROAD		 4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
Pres., Dry Van Division
 5. If Amendment, Date Original Filed(Month/Day/Year)
(Street)

PHOENIX, AZ 85043		 6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Beneficially Owned
1.Title of Security
(Instr. 4)		 2. Amount of Securities Beneficially Owned
(Instr. 4)		 3. Ownership Form: Direct (D) or Indirect (I)
(Instr. 5)		 4. Nature of Indirect Beneficial Ownership
(Instr. 5)
Common Stock, par value $0.01 per share 35.4353
I
Company Sponsored 401(k)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly. SEC 1473 (7-02)
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Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 4)		 2. Date Exercisable and Expiration Date
(Month/Day/Year)		 3. Title and Amount of Securities Underlying Derivative Security
(Instr. 4)		 4. Conversion or Exercise Price of Derivative Security 5. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 5)		 6. Nature of Indirect Beneficial Ownership
(Instr. 5)
Date Exercisable Expiration Date Title Amount or Number of Shares
Stock Option (Right to Buy) 10/13/2005 10/12/2010 Common Stock, par value $0.01 per share 844 $ 2.8518 D  
Stock Option (Right to Buy) 09/18/2005 09/17/2010 Common Stock, par value $0.01 per share 3,130 $ 4.8889 D  
Stock Option (Right to Buy) 06/05/2005(1) 06/04/2012 Common Stock, par value $0.01 per share 2,475 (1) $ 8.4445 D  
Stock Option (Right to Buy) 08/07/2006(2) 08/06/2013 Common Stock, par value $0.01 per share 3,038 (2) $ 11.4356 D  
Stock Option (Right to Buy) 03/19/2007(3) 03/18/2014 Common Stock, par value $0.01 per share 5,063 (3) $ 10.5378 D  
Stock Option (Right to Buy) 04/26/2008(4) 04/25/2015 Common Stock, par value $0.01 per share 4,500 (4) $ 14.48 D  
Stock Option (Right to Buy) 05/18/2009(5) 05/17/2016 Common Stock, par value $0.01 per share 3,500 (5) $ 18.75 D  
Stock Option (Right to Buy) 05/19/2009(6) 05/18/2016 Common Stock, par value $0.01 per share 1,000 (6) $ 18.77 D  

Reporting Owners

Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
Liu Michael K
5601 WEST BUCKEYE ROAD
PHOENIX, AZ 85043		       Pres., Dry Van Division  

Signatures

/s/ Michael Liu 04/03/2007
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 5(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) 1,650 shares of common stock are currently vested; the remaining 825 shares of common stock will vest on June 5, 2007
(2) 607 shares of common stock are currently vested; the remaining shares will vest as follows: 608 shares on August 7, 2007; 607 shares on August 7, 2008; 608 shares on August 7, 2009 and 608 shares on August 7, 2010
(3) 1,012 shares of common stock are currently vested; the remaining shares will vest as follows: 1,013 shares on March 19, 2008; 1,012 shares on March 19, 2009; 1,013 shares on March 19, 2010 and 1,013 shares on March 19, 2011
(4) This option will vest in equal shares of 900 on April 26, 2008, April 26, 2009, April 26, 2010, April 26, 2011 and April 26, 2012
(5) This option will vest in equal shares of 700 on May 18, 2009, May 18, 2010, May 18, 2011, May 18, 2012 and May 18, 2013
(6) This option will vest in equal shares of 200 on May 19, 2009, May 19, 2010, May 19, 2011, May 19, 2012 and May 19, 2013

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