Abstract: The multigrid numerical method is used to study elastohydrodynamic lubrication (EHL) problems with real rough surfaces in line and point contacts. After random rough surface samples are given, problems under different loads and roughnesses have been calculated. The results show that because of the function of the velocity item in Reynolds equation, the pressures induced by the corresponding roughnesses make the rough surface flattened in both line and point contacts, especially under heavy loads. The variat...