The influence of S and N in the V2O5/TiO2 catalyst system on the activity was evaluated for the selective catalytic reduction (SCR) of NOX. The VTi1 (S/N/Ti = 3:1:100) with wide temperature window has the highest catalytic activity. The properties of the catalysts were characterized by physicochemical measurements, including X-ray diffraction, BET surface area, NH3 temperature-programmed desorption, H-2 temperature-programmed reduction and O-2 temperature-programmed desorption, and so on. The structure, surface area, Lewis acidity, reducibility and active sites of the catalyst were significantly influenced by adding S and N. The results of ultraviolet-visible spectroscopy and electron paramagnetic resonance indicated that the presence of the strong electron interactions between dispersed vanadia and TiO2 species and more active oxygen species on the surface of catalyst. This work provides new insights into the effect of active oxygen species on the catalytic conversion of the nitrogen oxides.