In this paper, CeO2 was synthesized and used as carrier, meanwhile, MnOx was supported by different methods. The NH3-SCR activity of MnOx/CeO2 at low temperature has also been studied. The results show that the performance of the MnOX/CeO2 catalyst prepared by hydrothermal deposition method (MC-h) can reach up to 80% at 180 ℃, while the impregnation method (MC-i) is only 70% at 180 ℃. Testing results indicate that the catalysts synthesized by the hydrothermal deposition method have larger specific surface area and higher reducibility, and manganese oxide existed in the form of nanorods is more favorable for the contact between the active component and the reactive gas. All of these are beneficial to the SCR reaction.