The microwave coprecipitation method was used to synthesize α-Ni0.8Co0.2（OH）2 precursor for preparing LiNi0.8Co0.2O2 cathode material. The precursor α-Ni0 8Co0.2（OH）2 was mixed with LiOH·H2O and then calcined in O2 for 10 h at different temperatures（700℃，800℃，900℃）.XRD，SEM analyses and electrochemical tests were used to study the physical and electrochemical performance of the cathode material. With increasing calcination temperature，the characteristic peaks of the cathode materials became stronger and sharper，corresponding to a perfect crystalization. The results of electrochemical tests indicate that the sample LiNi0.8Co0.2O2（900℃）showed excellent electrochemical properties，with an initial discharge capacity of 189. 1 mA·h·g-1 and an initial discharge efficiency of 92. 5%. After 30 cycles，the discharge capacity was still 148 mA·h·g-1，showing good cyclic stability.