In this paper, a series of W-x/Ag/Al2O3 catalysts with different tungsten contents (0, 0.04, 0.06, 0.08, and 0.10 g/g) and 0.03 g/g silver for selective catalytic reduction of NO with methanol under excess oxygen (methanol-SCR), were prepared with a traditional impregnation method. At a gas hourly space velocity (GHSV) of 30 000h(-1), the operating window of NO conversion (NO conversion above 50 %) shifted to a higher temperature region as the tungsten content increased. Importantly, the operating window of NO conversion over combined catalysts containing W-8/Ag/Al2O3 in the front and Ag/Al2O3 in the rear (W-8/Ag/Al2O3+Ag/Al2O3), was wider (65 degrees C) than that of the single W8/Ag/Al2O3 catalyst (50 degrees C) or Ag/Al2O3 catalyst (41 degrees C). Further, the CO concentration over the combined catalyst was lower than the single W8/Ag/Al2O3 catalyst. The characterization results demonstrated that there are strong interactions between tungsten and silver which contribute to the formation and stabilization of oxidized silver species.