An experimental investigation has been conducted to reduce NOx from combustion flue gases by means of corona discharge activated ammonia radical shower methods. Experiments were conducted for pure nitrogen-NO, wet air-NO, and simulated combustion gases at a hue gas how rate 3 l/min. The results showed that the NOx reduction increased with increasing activation voltage. In case of wet air-NO mixture gases, a NOx reduction efficiency of 100% was achieved. The deposited NH4NO3 aerosol particles have a significant effect on the stability of intense streamer coronas. Trace amounts of N2O in an exhaust gas and NH4NO3 aerosol particles deposited on the electrodes were observed as by-products.