The effect of feed gas composition on the removal of NO and the formation of byproducts in a positive-pulsed corona discharge reactor were experimentally examined. The mechanism for the removal of NO was found to largely depend on the gas composition. In the absence of oxygen, most of the NO removed was reduced to N-2; on the other hand, the oxidation of NO to NO2 was dominant when oxygen was present although the content was low. The removal of NO decreased with the water vapor content due to the decreases in the power delivery and the formation of ozone, The production of N2O increased with the pulse repetition rate, and the presence of NH3 and SO2 enhanced it. Byproducts generated from propane used as additive were identified and analyzed. The main byproducts other than carbon oxides were found to be ethane and formaldehyde, but their concentrations were negligibly small.