U.S. Xpress Enterprises (USX) 10-K 2005 FY Annual report

Exhibit 32.1

Form of 906 Certifications

CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350 AS ADOPTED

PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Annual Report of U.S. Xpress Enterprises, Inc. (the “Company”) on Form 10-K for the year ending December 31, 2005 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), the undersigned hereby certifies, pursuant to 18 U.S.C. § 1350 (as adopted pursuant to § 906 of the Sarbanes-Oxley Act of 2002) that he is the Chief Executive Officer of the Company and that: (1) the Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, and (2) the information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

/s/ Max L. Fuller                                

Max L. Fuller

Co-Chairman of the Board of Directors,

Chief Executive Officer and Secretary

Date: March 10, 2006