The ammonia selective catalytic reduction (NH₃-SCR) technology is still necessary to further develop denitration catalytic materials which have good catalytic activity, high stability and environmental friendliness at relatively low temperature (<300 ℃). In this work, the Mn-Fe-O catalyst was prepared by oxalate co-precipitation method and modified with different contents of CeO₂ for low temperature NH₃-SCR of NO. The catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen adsorption-desorption, X-ray photoelectron spectroscopy (XPS), temperature programmed reduction or desorption (H₂-TPR, NH₃-TPD). The catalytic results show that as compared with pure Mn-Fe-O sample, Mn-Fe-O modified with suitable CeO₂ content shows much better performance for NH₃-SCR with 95% conversion of NO and a high N₂ selectivity at 80 ℃ under the same reaction conditions. CeO₂ modification increases the content of Fe ³⁺, Mn ³⁺ and Mn ⁴⁺, and the number of surface acid sites on the surface of Mn-Fe-O oxide, which contribute to the adsorption of NH₃ and the catalytic reaction. In addition, redox reactions among Fe ²⁺/Fe ³⁺, Mn ²⁺/Mn ³⁺/Mn ⁴⁺ and Ce ³⁺/Ce ⁴⁺ pairs improve the redox ability and stability of the catalyst.