Abstract: Polyphenylene sulfide (PPS) filter was treated by nitric acid to form PPSN filter. By the ultrasonic method, PPSN filter was loaded on 40% manganese molar fraction of MnO_x-CeO₂ which was calcined at 400℃ to form MnO_x-CeO₂/PPSN. The activity of MnO_x-CeO₂/PPSN was tested in the presence of NH₃ as reducing agent for selective catalytic reduction of NO. The influences of catalyst temperature, volume fraction of NH₃ and O₂, and catalyst loadings on the de-NO efficiency were studied too. It was found that MnO_x-CeO₂/PPSN filter with the catalyst loadings of 296g/m² showed higher de-NO efficiency under the conditions of temperature 130~160℃, NH₃/NO>1, and O₂ 5%. When the catalyst temperature, the volume fraction of NH₃ and O₂ are constant, de-NO efficiency of MnO_x-CeO₂/PPSN is higher with the catalyst loading increasing.