The CeO -V O -WO /TiO (CeO -VWT) catalysts were prepared by one-step and two-step impregnation methods. The effects of different loading of CeO and different preparation methods on De-NO activity of catalysts had been investigated. CeO helped to improve the De-NO activity and sulfur resistance. The optimal loading of CeO was 3% with the De-NO efficiency reached 89.9% at 140°C. The results showed that the De-NO activity of 3% CeO -VWT catalysts by one-step method was the same as two-step method basically and reached the level of industrial applications, the N selectivity of catalysts was more than 99.2% between 110°C and 320°C. In addition, CeO promoted the oxidation of NO to NO , which adsorbed on the Lewis acid site (V ═O) to form V ═NO and inspired the fast SCR reaction. Not only the thermal stability but also the De-NO activity of catalysts decreased with excess CeO competed with V O . Characterizations of catalysts were carried out by XRF, BET, XRD, TG and FT-IR. BET showed that the specific surface area of catalysts decreased with the loading of CeO increased, the active components content and specific surface area of catalysts decreased slightly after entering SO . Ammonium sulfate species were formed in poisoned catalyst which had been investigated by XRF, BET, TG and FT-IR. The largest loss rate of weight fraction was 0.024%·°C at 380°C–390°C, which was in accordance with the decomposition temperature of NH HSO and (NH ) SO .