The performance of selective catalytic reduction of NO over ceria-titania (Ce-TiOx)-based materials after aging in SO2 atmosphere in the presence and absence of O-2 was investigated, showing that O-2 gave acceleration on the deactivation of the samples for the enhanced SO2 adsorption and sulfation over ceria-based materials. FT-IR and TPD-MS over samples with 10wt%, 50wt% and 90wt% of CeO2 were carried out. The results indicated the poisoning effect of SO2 over Ce-TiOx catalyst for SCR is in accordance with the amount of sulfite or sulfate over Ce-TiOx with a certain percentage of CeO2.