Ce-Mn/TiO₂ mixed oxides catalysts were prepared by reverse co-precipitation (RC), conventional co-precipitation (C) and impregnation (I) methods for low-temperature selective catalytic reduction of NO_x by NH₃. The effect of the calcination temperature, aging time and space velocity on the de-NO_x activities of the 4Ce-10Mn/TiO₂-RC was investigated. The 4Ce-10Mn/TiO₂-RC catalyst exhibited a more excellent low-temperature activity and a higher SO₂ resistance than those prepared by the co-precipitation and impregnation methods. The NO conversion over 90% of in the temperature of 120 ∼ 330 °C was achieved, which only decreased from 99% to 85% after adding 5% H₂O at 180 °C for 1 h. The excellent performance of the 4Ce-10Mn/TiO₂-RC may be owing to its low crystallinity, high specific surface area, uniform dispersion of active sites, high content of Mn⁴⁺, Ce³⁺ and adsorbed oxygen species, acid sites on the surface. The XPS results showed electron transfer may exist between the manganese oxide and cerium oxide: Mn³⁺ + Ce⁴⁺→Mn⁴⁺ + Ce³⁺. Moreover, the in situ DRIFTS revealed the NH₃-SCR reactions over 4Ce-10Mn/TiO₂-RC and 4Ce-10Mn/TiO₂-I catalysts were mainly controlled by the Eley-Rideal mechanism.