The cyclic voltammograms of the copper electrode in Na2S solution was studied using cyclic volammogram?s technique.Three anodic peaks were observed in the anodic branch of the voltammogram?s. The peaks may be attributed successively to the formation of Cu2S, CuS and Cu2O. On the other hand, the cathodic branch shows four peaks. These peaks correspond to the reduction of copper oxide and copper sulfide formed in the anodic branch.