Owing to the manufacturing process, the surfaces of machine elements may be roughened. Therefore, analyses of surface roughness effects on the bearing performances show great importance. Based upon the stochastic model of rough surfaces of Christensen, a study of surface roughness effects on the performance characteristics of parabolic-film slider bearings is presented in this paper. According the results, the longitudinal roughness effects decrease the lubrication performances of bearings. However, the roughness effects of transverse patterns provide an improvement in the steady load capacity, the dynamic stiffness coefficient and the dynamic damping coefficient of the parabolic-film sliders