Abstract: A series of binomial formulae of △G°-T dependence and their diagram for the formation of oxides of Pb、Sn、In、Ga and Ce were given on the basis of calculated results of data from《CData Bank of the Thermodynamic Properties for the Inorganic Substances》. The oxide on the surface of solid metal Sn and Pb-Sn alloys, found by corrosion in atmosphere, dry and heat air or vapor, was defined as SnO₂ using XPS. A similar result is obtained for solid Pb. The corrosive layer on the surface of solid Pb was defined as Pb₃O₄ which was formed by passing of dry and heat air over Pb.