The V2O5 catalysts supported on TiO2-SiO2-MoO3 (TSM) prepared by the coprecipitation method were investigated for the selective catalytic reduction (SCR) of NO by NH3 at low temperatures. The V2O5/TSM catalyst with 7-13 wt% SiO2 was found to exhibit a superior SCR activity and a good sulfur tolerance at low temperatures (< 250 degrees C). The presence of highly active polymeric vanadates formed by the incorporation of MoO3 to TiO2-SiO2 and superior redox properties seems to enhance SCR activity, and furthermore the very lower SO2 oxidation activity due to the higher acidity leads to the remarkable improvement of sulfur tolerance.