Abstract: The traction characteristics of synthetic lubricants at high sliding speedcontacts are studied according to the thermal partial elastohydrodynamic lubrication theory for consideration of surface roughness effect and the Ree-Eyring theological model for mirroring the non-Nowtonian behavior of the lubricant. The analysis program developed incorporates a computational algorithm which can efficiently and accurately find out the pressure and temperature distributions and determine the traction coefficient of synthetic lubricants. The variations of the traction coefficient of synthetic lubricants with the load, rolling and sliding speed, lubricant viscosity and ambiance temperature are obtained and the comparison between the calculated results presented in current work and the experimental results of ref. [2] is also shown. The method adopted in present investigation is instructive for dynamic study of aviation high-speed rolling bearings.