Low temperature NH3-SCR of NO is strongly needed due to its availability in industrial furnaces and energy-conserving feature. MnOx-CeO2/TiO2 (MnCe/Ti) with different Ce doping contents were prepared and their catalytic activities for NH3-SCR under 100-400℃ were experimentally examined. The results suggest that addition a small amount of Ce (Ce/Ti mole ratio=0.05) improves the exposure of Mn atoms on catalyst surface and exhibits highest NH3-SCR activity at 100-200℃, on which above 98% of NO is abated at 175℃. Further increase the Ce contents decreases the catalyst performance instead. Moreover, NH3-SCR of NO under oxidizing or reducing conditions confirms the oxygen species bounded to the exposed Mn atoms are easier to be released and the resulted oxygen vacancies are more likely to be replenished by O2 at low temperature. In addition, the SO2 resistance of MnCe/Ti is also enhanced by Ce modification, mainly due to the inhibition of the accumulation of ammonium sulfates and the preferential sulfation of the Ce dopants.