Effects of zinc ions, agitation rate, pH values and temperatures of zinc sulphate solutions on cobalt removal by zinc cernentation have been studied. Results show that for ions have a considerable effect on cobalt removal using for powder. It is easy to remove cobalt by cementation using zinc powder when there are not any zinc ions in cobalt sulphate solutions. On the contrary, it is hard to remove cobalt from cobalt sulphate solutions containing zinc ions. Rate of cobalt removal using zinc power decreases when the temperature of zinc sulphate solutions is below 75℃. Rate of cobalt removal increases when pH valuses of the solutions decrease, however, the depletion of zinc powder increases if the pH values of solutions are very low. In this way, the cost of production is raised. So the pH value of zinc sulphate solutions must be kept 3.8-4.5