Perovskite-type oxides have been tested for the reduction of NO usiilg propane as reductant. Especially the perovskite-type oxides were prepared by malic acid method to increase the surface area. The effects of several variables such as reaction temperature, the concentration of reactants, residence time have been also investigated. In addition, in the presence of water and SO₂, the activity of catalysts has been examined. In the LaCoO₃ type perovskite oxide, the partial substitution of Ba into A site enhanced the activity of NO decomposition and the activity shows the high activity in wide reaction temperatune. In addition, the partial substitution of Fe into B site also enhanced the conversion of NO.