Abstract: Owning to insufficient self-conditioning ability affected by tiny chip,sapphire lapped by fixed abrasive pad is limited in industry.SiC particles were added to slurry to assist chips in conditioning pad in this study.Two different pads,one containing diamond abrasives(grain size 20-30 μm)and the other not,were made for experiment.The material removal rate and topography of sapphire at different conditions were compared to explore the influence of SiC on lapping process.Resultsshowed that the SiC particles added to slurry assisted in improving self-conditioning of pad by increasing wear of resins and exposing diamond abrasives out of sub-surface.Material removal rate of slurry with SiC particles was 14 times higher than that of slurry without SiC.