The LiNixCo1-2xMnxO2 cathode materials for lithium-ion batteries were synthesized by an improved high temperature solid-state method. The effects of x values（x=0.20, 0.33, 0.40, 0.45, Li/（Ni+Co+Mn）molar ratios n(Li)/n(M)=(1.00, 1.05, 1.10, 1.15)，sintering temperatures（800, 900, 950, 1000 ℃）and sintering times (8, 12, 16, 20 h) on the performances of LiNixCo1-2xMnxO2 were studied and the structures of products were characterized by X-ray diffraction (XRD). The results showed that the cycling performance was improved for higher Co content. The cathode material with excellent electrochemical performance was obtained by sintering the mixed raw materials with n(Li)/n(M)=1.10 at 950~1000 ℃ for 20 h