A new type of three way catalyst was developed in order to reduce HC, CO and NOx in cold exhaust gas. This catalyst consists of double layer, and has a base support material of alumina and oxygen storage components (OSC) loaded with active metals including platinum. palladium and rhodium. It has good light-off performance and high catalytic activity. This catalyst includes two types of OSC. One is CeO2, and the other is CePrO2 that makes possible to improve NOx conversion at high exhaust gas temperature. 8 refs., 13 figs., 2 tabs.