LiNi1-xCOxO2 cathode material was prepared by a theological phase reaction method with LiOH center dot H2O and Ni1-xCox(OH)(2) as starting materials. The mixture of reactants and a proper amount of water reacted to form a theological precursor, and the dried precursor was calcined in flowing oxygen based on the results of thermogravimetric. The calcination temperature has a remarkable effect on the electrochemical performance of the samples. The sample calcined at 730 degrees C for 6 h has the best electrochemical properties. The cobalt content has significant effect on the electrochemical performance for LiNi1-xCoxO2 material. When x-value is less than 0.08, the first discharge capacities and capacity retentions decrease rapidly. The LiNi0.9Co0.1O2 material has the largest initial discharge capacity and the better electrochemical performance. This method is simple and effective for preparing cathode materials for lithium batteries. (C) 2007 Elsevier B.V. All rights reserved.