Abstract: The rare earth oxalates prepared using rare earth sulfate as raw material by oxalate deposition were calcined in different processes to get rare earth oxides (rare earth polishing powders). The decomposition behaviors of rare earth oxalate were characterized by TG-DSC, and the crystallization, micro-morphology and polishing performance of the grains of rare earth oxides were studied by XRD, TEM and polishing machine. Results show that crystal phase of the rare earth oxides after calcining at different temperatures were all cubic CeO2. Incompletely developed hollow spherical particles were obtained when the rare earth oxalates were calcinated at 550 ℃ for 3 h. And the rare earth oxide grains were completely developed and formed spherical particles with clear edges at 950 ℃. The material removal rate increased with the rise of calcining temperature and prolongation of holding time, but raising calcining temperature can had a better effect. The sample prepared at 950 ℃ for 3 h had the best material removal rate of 368 nm·min-1.