The cathode material LiCo 1-x Lax O2 ( x = 0, 0.01, 0.02, 0.05 ) for Li- ion battery was prepared in solid phase. Effects of La dopant on the structure were analyzed by X-ray diffraction, and the morphology of the samples was observed by scanning electron microscopy. The results show that the structure of LiCoO2 becomes more and more non-perfect with the increasing content of La and some impurity peaks appear in the XRD patt when the La content reaches 0.05. Meanwhile, a high synthesis temperature is advantageous to the intact and unitary compound. The initial discharge capacity of doped material containing La ( x = 0.01 ) synthesized at 900 ℃ reaches 160 mAh/ g by charge-discharge test, which prior to that of non-doped material synthesized under the same condition . However, the increasing La content deteriorates the cycling performance. Therefore, the appropriate cnotent of La is 0.01 and the optimum synthesis temperature is 900 ℃ .