The friction force of wafer surface plays an important role in removing material of wafer surface and the friction force distribution on wafer surface has a direct influence on nonuniformity of material removal in wafer CMP process. In this paper, models of friction force distribution and friction force on wafer surface were built according to the CMP process. Then the relationships between friction force and CMP process variables, such as the motion variables and pressure, are obtained. Measuring data of friction force on wafer surface are accord with analytical results. The research of this paper is helpful to further understanding the material removal mechanism in wafer CMP.