An exhaust gas purifying catalyst of the present invention contains alumina, and ceria loading palladium and platinum, and the ratio of palladium (IV) oxide to palladium (II) oxide by peak separation of the 3d orbital of palladium in X-ray photoelectron spectroscopy is within a range from 70:30 to 99:1. Thereby, the catalyst is capable of reducing the CO concentration and increasing the H.sub.2 concentration in an exhaust gas even after durability at high temperature.