The copper-based powder metallurgy friction pairs are widely used in hydro-viscous drive. In order to research the frictional characteristics of friction pairs,the frictional coefficient under different working conditions is tested by using MM-Ⅲ friction and wear performance tester. The influences of relative rotational speed,contact pressure and temperature on frictional coefficient are analyzed. The results show that the frictional coefficient changing with relative rotational speed is similar to the Stribeck curve,which drops sharply first and then rises slowly. With the increase of the contact pressure,the viscous shear effect of oil film become lower,and the contact frictional coefficient gradually decreases. In addition,temperature has a small effect on contact frictional coefficient. Therefore,using MM-Ⅲ friction and wear performance tester,the variation of frictional coefficient of copper-based powder metallurgy friction pairs with relative rotational speed,contact pressure and temperature can be obtained,which provides a theoretical basis for the study on mixed friction torque model and speed regulation stability of hydro-viscous drive.