Poisoning by Na is one of the major issues for the commercial SCR catalyst. In this study, Ce(SO4)2 was added to the catalyst system of V2O5/TiO2 to enhance its resistance to Na poisoning. The results show that the addition of Ce(SO4)2 increases the NOx conversion of the V2O5/TiO2 catalyst at medium temperatures of 330°C–450°C. After being doped with sodium with a molar ratio of Na/V = 1/1, the V2O5-Ce(SO4)2/TiO2 catalyst still shows excellent DeNOx efficiency, about 40% higher than the commercial V2O5-WO3/TiO2 catalyst. The fresh and Na-poisoned catalysts were characterized using XRD, SEM, NH3-TPD and H2-TPR. The results show that the Ce(SO4)2 addition remarkably strengthens the surface acidity and redox ability of the V2O5/TiO2 catalyst. Furthermore, the TPD results show that the V2O5-Ce(SO4)2/TiO2 catalyst can maintain its surface acidity after being doped with Na, while the acidity of the V2O5-WO3/TiO2 catalyst dramatically decreases. The redox ability of the catalyst can also be retained more effectively when Ce(SO4)2 is added to the catalyst system.