We investigated efficiency of removal of NO and NOx for applied voltage, repetition frequency and energy according to reactor type (wire-plate and wire-cylinder type reactor). Characteristics of Reactor type by pulsed corona discharge could be analyzed through these Results. Because it is very difficult to measure the conduction current for calculation of energy transferred into the reactor in the corona discharge, conduction current was obtained indirectly and the necessary energy for removal of NO and NOx was calculated from conduction current. Removal efficiency of NO and NOx for control variable (applied voltage, pulse repetition frequency, energy transferred into the reactor and removed quantity etc.) in the wire-cylinder type reactor was higher than that in the wire-plate type reactor.