In this study, we analyzed the NOx removal efficiency and particle size distribution by the pulsed corona discharge process and investigated the effect of several process variables. The NO removal efficiencies and the particle characteristics were measured and analyzed as the function of initial concentrations of NO, H2O, and NH3 at the inlet, applied voltage, pulse frequency and residence time of gas stream. As the applied voltage and the residence time increased, or as the initial concentration of NO decreased, the NO removal efficiency increased. The higher NO removal efficiencies were obtained with the discharge electrode of larger diameter. The changes of initial NH3 and H2O concentrations did not affect the NO removal efficiency significantly. The particle concentration and size of ammonium nitrate salts increased with the increases of initial NO concentration, residence time and applied voltage.