The influences of surface speed effect on elastohydrodynamic lubrication(EHL) was investigated by experiment.The experiment was based on the improved classical balldisc device,in which the angle of ball and disc velocity direction can be changed by arc guideway,the speed and rotation of servo motor can be controlled by programmable logic controller（PLC）and servo amplifier.By using the interferometry technique,the oil film shape was observed under light load with different angle between the ball and disc velocities.The midsection film thickness profile was obtained by MBI software.It is found that,with the increasing of the angle between the two contact surface velocities,the oil film thickness is decreased,the minimum film thickness is decreased firstly,and then increased when the angle reaches a certain value.With the increasing of the angle between the two contact surface velocities,the asymmetry of the oil film shape along the sliding direction is increased.This phenomenon can be explained by the mechanism of the temperatureviscosity wedge.