Abstract: Ironmanganese composite oxides doped with CeO2 as desulfurizer were prepared by coprecipitation and characterized by XRD, SEM, TG and XPS. Its performance in desulfurization was investigated at 325℃ and atmospheric pressure. The results illustrated that CeO2 doping may influence the crystal size, dispersion and surface configuration of ironmanganese composite oxide. As compared with the desulfurizer without CeO2, smaller crystal size and better dispersion can be achieved through CeO2 doping. The content of chemisorbed oxygen on the desulfurizer surface was increased through the addition of 3% CeO2 in ironmanganese composite oxides; its reduction and desulfurization performance were also improved largely. The addition of proper content of CeO2 in ironmanganese composite oxide may increase the active sites for COS adsorption and then enhance its desulfurization activity in COS removal, however, excess amount of CeO2 may cause a negative effect on the desulfurization capacity.