In this work, we present an experimental study of the reduction of NO and the creation of NO2 by positive corona discharge in N2/O2 mixture (95% N2, 5%O2), where 200ppm of NO are injected at atmospheric pressure. The corona discharge was generated using a wire- to- cylinder reactor. The applied voltage is 5kV and 7 kV and it was maintained for 50 minutes. Ultraviolet absorption spectroscopy operating in the wavelength range 190-330 nm was used to identify the species and quantify their concentration, According to Beer Lambert law who give concentration from absorbance. The temperature was maintained constant for 300K. The obtained resultant show nitrous oxide NO has been destroyed with the augmenta¬tion of corona current. We note different times to NO removal, 50 minutes at 5 kV and 20 minutes at 7 kV. And we observe the creation of NO2 and the apparition of ozone O3.