Reduction of NO by CO in N-2 was experimentally investigated in a wire-in-tube pulsed corona reactor combined with CuO catalyst. The pulsed corona was produced by applying a positive pulsed high voltage (peak voltage 16-22 kV, pulse frequency 50 pps) to the wire electrode and the catalyst was coated on the surface of the aluminum film, the grounding electrode attached to the inner surface of the tube. It was demonstrated that NO could be effectively reduced to N-2 under nonthermal plasma produced by pulsed corona discharge, and the NO2 yield was significantly suppressed with the existence of CO in the gas stream. For the pulsed corona reactor combined with CuO catalyst, the reduction of NO was 10-20% higher and NO2 production was 50% lower than that of without catalyst in the reactor at room temperature, showing that CuO catalyst works effectively for the reduction of NO under pulsed corona discharge. A complete reduction of 500 ppm NO in a gas stream containing 1% CO was achieved at about 473 K with a pulse voltage of 18 kV in the reactor combined with CuO catalyst.