The electrochemical characteristics and the catalytic activity, of Pt-tungsten oxide and Pt-titanium, oxide catalysts in polymer electrolyte fuel cell were investigated by cyclic voltammetry and in fuel cells. Fuel cell performances for those catalysts at 80 degreesC with, humidified hydrogen and oxygen increased with increasing added oxide content in the catalysts up to a certain content. Adsorption characteristics for hydrogen and oxygen on the surface of platinum were greatly influenced by added oxide content in the catalysts. It was, also obtained that the electrochemically active surface area of these catalysts was influenced by their oxide content.