Abstract: The transmission efficiency and fatigue life of gears are closely related to the machine process mode of tooth surface. In present study, three-dimensional line contact model and Zaretsky contact fatigue life calculation method were employed to investigate the effect of surface topography on the Stribeck curve and contact fatigue in a wide range of operating speed, with four machined surface (shaved surface, ground surface, honed surface and polished surface). And the influence of friction coefficient on the fatigue life was studied as well. The obtained results show that, under the condition of full film lubrication, the influence of interfacial friction on fatigue life was limited, and the friction coefficients of all kinds of composite surfaces were basically the same, but the fatigue life of each combination surface was much different. The fatigue life of polished composite surface was the longest. In mixed lubrication, the variation of friction changed significantly. The friction coefficient of grounded composite surface was relatively large, while the polished composite surface was the smallest, and the relative fatigue life between composite surface decreased obviously in mixed lubrication. It should be noticed that the interfacial friction coefficient and fatigue life were complicated functions of surface roughness.