To investigate the lubrication performance of elastohydrodynamic lubrication(EHL) between contact pairs in rolling bearing,a nonNewtonian thermal microEHL model between a cylindrical roller and an outer ring was established.The difference for Newtonian and nonNewtonian fluid under the condition of different characteristics shearing stress,slideroll,and load was analyzed.The effect of the amplitude and wavelength of the roughness on thermal microEHL was discussed.Results show that,the effect of the characteristic shearing stress on the temperature is much larger at the end part of the roller than in the middle part of the roller.Under the influence of the roughness,the fluctuation amplitude of the oil temperature is increased with the increase of the characteristic shearing stress.With the increase of the slideroll ratio and the load,the oil temperature and friction coefficient for Newtonian and nonNewtonian fluid are increased,and the oil temperature rise and the friction coefficient of Newtonian fluid are obviously larger than those of the nonNewtonian fluid.The fluctuation of film thickness,pressure and temperature in the contact region is increased with increase of the roughness amplitude,and tends to be stable with increase of the roughness wavelength.Due to the roughness,the local temperature rise in the middle of the roller is increased with the increase of slideroll ratio and load.