The effect of SnO2 interfacial layer on the electrocatalytic activity of PbO2 / SnO2 / Ti electrode towards chlorine evolution has been studied in sodium chloride solutions by polarization and cyclic voltammetric measurements. The results show that the electrocatalytic activity increases when the sintering temperature and time of the interfacial layer is increased. X-ray diffraction studies reveal that the quantity of beta-PbO2 phase formation is more than that of alpha-PbO2 phase under these conditions. The service life of PbO2/SnO2/Ti electrode towards oxygen evolution in acidic solution improves when the interfacial layer is doped with 1 mole % Ru.