Abstract: CaZrO₃was prepared by solid reaction for 3 h at different sintering temperatures using Ca(OH)₂and m-ZrO₂(1:1 by mole) as raw materials with the different contents of CuO by mass as additive. The effects of CuO on sintering properties, phase composition, and microstructures of CaZrO₃were studied by apparent porosity density determinator, X-ray diffraction (XRD), scanning electron microscope (SEM), and X'Pert plus software. The results show that, CaZrO₃can be synthesized by Ca(OH)₂and m-ZrO₂at 1500 ℃ to 1600 ℃ sintered for 3 h. For the CaZrO₃samples without CuO, the sharking is 11.22%, bulk density is 3.37 g·cm^-3, apparent porosity is 15.6%, and grain size is 3.58 μm. For the CaZrO3 samples added 1.5% CuO by mass, the sharking is 19.68%, bulk density reaches to 4.07 g·cm^-3, apparent porosity is 7.6%, and grain size is 5.14 μm. The reason could be summarized as the low melting reaction product (CaO-CuO) generated by CuO and CaO at high temperature, which could form the liquid at high temperature and promote the sintering.