By assuming the existence of a ridge or groove on one surface,numerical calculations were implemented to investigate the influence of rough surface on line contact thermal elastohydrodynamic lubrication (EHL) problem with large slide-roll ratio.It is found that both the surface ridge and groove cause local fluctuations in oil pressure,film thickness and temperature rise profiles,and among them the pressure fluctuation is the most obvious.At a relatively small slide-roll ratio,either the surface ridge or groove influences the pressure,film thickness and temperature rise profiles greatly,and the variations become smaller with the increase of the slide-roll ratio.With the increase of the slide-roll ratio,the fluctuations in pressure,film thickness and temperature rise profiles caused by the increase of the ridge amplitude become smaller.The results are of significance in revealing the oil film formation and failure in ball screws and retainerless rolling element bearings etc.