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.