The study investigated NO reduction by N radicals produced by barrier discharge in nitrogen and the possible effect of TiO2 catalyst on this reaction. The experiments for NO reduction were carried out at temperatures ranging from room temperature to 140 degrees C and at NO concentrations ranging from 200 to 800ppm. The experimental results were described by a model which was based on six main reactions for the calculation of the NO and NO2 concentrations. The analysis of model suggested two simple methods for the estimation of nitrogen radical production efficiency which in present study was 2ppm/(J/L). The model also confirmed that N radicals are used very efficiently in the reduction of NO and this process can't be improved by the catalyst. Nonetheless, experiments showed that the presence of TiO2 catalyst improved the removal of NO. The experimental results can be explained by surface processes taking place with NO2 with the help of other plasma produced nitrogen species.