Manganese oxides supported palygorskite (MnOx/PG) catalysts used for low-temperature selective catalytic reduction of NO with NH3was modified by doping cerium oxide as additive for enhancement of its performance. The effects of doped cerium content on catalysts' activity were investigated. It was found that the NO removal efficiency of Mn8Ce5/PG catalyst was remarkably higher than Mn8/PG catalyst especially at low temperatures, revealing that the addition of cerium oxide effectively enhanced the catalysts' SCR activity. Catalysts were characterized by BET, XRD, XPS to explore the relation between structural properties and increasing in SCR activity via modification. Results showed that the doping of cerium oxide has improved the dispersion of manganese oxides as active species. And furthermore, the stability of surface MnO2was also improved which was suggested to be the main reason for the enhancement of catalysts' activity.