The effects of sulfation of V/Sb/Ce/Ti catalyst on the SCR activity was examined. Sulfation treatment was carried out at 250, 300, 400, and 500 °C for 1 h. As sulfate species (SO₄^2-) formed, the NH₃ adsorption capacity on the surface of catalyst increased. It reacted with NO to be converted into H₂O and N₂. In addition, as NO₂ was formed by the reaction of NO and O₂ in the sulfated catalyst, fast SCR reaction occurred. Increase in the surface Ce³⁺ ratio of the sulfated catalyst increased the NO to NO₂ oxidation. The excellent SCR activity can be attributed to an enhancement in active oxygen species and chemisorption of NH₃. When considering the SCR activity for V/Sb/Ce/Ti catalyst, the optimal conditions for sulfation were 500 °C.