The growth kinetics of both PbSO4 and PbO layers has been studied further. The growth rate of the PbSO4 layer depends on the migration of the SO42- ion through the micropores while that of the PbO layer depends on the migration of the Pb2+ and OH ion in the PbO layer and the H+ ion in the PbSO4 layer. The PbSO4 and PhO layers grow at the PbO . PbSO4/PbSO4 and metal/PbO interfaces, respectively. In the PbSO4 layer the concentrations of the SO42- and H+ ions decrease linearly with the distance from the PbSO4/bulk solution interface and the largest potential drop appears at the PbO . PbSO4/PbSO4 interface. Yet the concentrations of the Pb2+ and OH- ions remain unchanged and the diffusion potential drops linearly in the PbO layer.