Ce 0.5 Zr 0.5 O 2 , Ce 0.5 Zr 0.2 Mn 0.3 O 2 and Ce 0.5 Mn 0.5 O 2 were prepared by citric acid sol–gel method. The effect of manganese on the structural and redox properties of ceria-based mixed oxides was investigated by means of powder X-ray diffraction, X-ray photoelectron spectroscopy, Brunauer–Emmett–Teller analyses, temperature-programmed reduction and catalytic activity evaluation in the presence of excess O 2 . The results showed that some Mn cations could enter into the ceria lattice to form solid solutions. Mn 3 O 4 appeared due to the instability of the mixed oxides with increment of the Mn doping ratio while another oxide Mn 2 O 3 is detected in the physical mixture of ceria and manganese oxide. These Mn-doped mixed oxides, especially Ce 0.5 Mn 0.5 O 2 , presented better catalytic activities than Ce 0.5 Zr 0.5 O 2 and even Pt-loaded catalyst for total oxidation of C 3 H 8 and oxidative sorption of NO in the presence of excess oxygen. The oxidation ability of Mn and the strong interaction between Mn and Ce were suggested to promote the oxygen storage/transport capacity of the mixed oxides as well as reactive adsorption of nitric oxide and hydrocarbons.