Exhaust flue gas from fossil fuel combustion usually contains a large quantity of SO2 and NO. In this paper, a process of simultaneous removal of NO and SO2 by ozone oxidation combined with NaOH absorption was chosen. The main investigations involved O-3 decomposition, factors affecting NO oxidation (O-3 dosage, reaction temperature, NO initial concentration, and presence of SO2), and NaOH absorption. The results indicated O-3 decomposition rate increased as temperature rose and was less affected by initial concentration of O-3. The optimal temperature for NO oxidation was 150 degrees C. NO oxidation efficiency increased with the increase of O-3 dosage at a fixed temperature. NO initial concentration and the presence of SO2 had a slight effect on NO oxidation. The NO oxidation efficiency remained above 90% when n(O3)/n(NO) was 1. Absorption by NaOH solution resulted in the final removal of above 99% NO, 90% NO2, and nearly 100% SO2 at pH above 11.