Two kinds of different Co-S microspheres with novel structure are synthesized by liquid phase chemical method (hydrothermal method and solvothermal method), and their formation mechanisms are also constructed. The electrochemical properties as negative electrode for alkaline secondary batteries are first performed using LAND battery test instrument. Co-S nest-like spheres electrode displays high reversible discharge capacity of 250 mAh g(-1) and excellent cycle stability at current density 200 mAg(-1). The discharge curve and CV curve confirm that the reaction occurring on Co-S alloy electrode is a reversible redox reaction of Co. The higher specific surface areas of Co-S nest-like spheres may be responsible for the higher discharge capacity. (C) 2010 Elsevier B.V. All rights reserved.