Abstract: A material removal rate (MRR) model of silicon wafers was built based on friction and abrasion behaviors in wafer chemical mechanical polishing (CMP). Different slurries were designed for CMP tests of MRR. MRR results were obtained from the mechanical action of abrasives, the chemical action of slurry, and the interaction action between them. From the results it is concluded that the mechanical action produced by abrasives is the main mechanical action in wafer CMP process, and the MRR is mainly produced by the interaction between the mechanical action and the chemical action.