SnO2–Sb2O3 or SnO2-Sb2O3-MnO2/ PbO2 electrode on aluminum substrate were prepared by thermal decomposition、electroless plating and electrodeposition .The surface morphology of coatings were investigated by using scanning electron microscope(SEM). The results show the effects of composition of solution and thermal oxidation temperature on the microstructures of the coating were considerable. The structure of oxide coating become refined with the thermal de- composition temperature increasing. The oxide coating without Mn is coarser than those with Mn. The surface of α-PbO2 and β-PbO2 deposited on the oxide coatings without Mn prepared at 450°C are compact and even, the electrocatalyst of the electrode is optimumest.