Commercial V2O5-WO3/TiO2 (abbreviated to VWTi) SCR catalysts are modified with Ce and different contents of Cu in wet impregnation method to improve their alkali metals resistance, which is beneficial for prolonging their service life. After K poisoning, NOx conversion of VWCeCuTi sample modified with 0.30% Ce and 0.05% Cu is 89% at 350 degrees C, which is obviously higher than that of VWTi with a 50% NOx conversion. A series of characterization tests were conducted and verified that the ratio of V5+ and the surface-active oxygen on VWCeCuTi sample increases due to the interaction between V, Ce and Cu. Additionally, with the addition of Ce and Cu, surface acid sites are increased and their stability is strengthened. The enhanced redox property and surface acidity contribute together to the excellent K resistance of VWCeCuTi catalyst.