In order to develop a highly sulfur capacity and reactive COS removal sorbent from syngas, Fe-Mn-Ce oxides were studied in this work. The sorbents can remove COS from 1.5% to less than 0.3 mg/m(3) in appropriate conditions. Sulfur capacity of the fresh sorbent was about 20 gS/100 g sorbent in the temperature of 320-400 degrees C. Tests showed that Fe2O3 was reduced to Fe3O4 or FeO with the simulated syngas and the presence of Fe3O4 can account for the high COS removal efficiency. The reactivity of the sorbent decreased when Fe3O4 was partially reduced to FeO. It was found that the desulfurization behavior was also influenced by the calcination temperatures, desulfurization temperatures, and gas compositions. High calcination temperature has a negative effect on the desulfurization performance of the sorbent due to lower BET. Hydrogen favors the desulfurization efficiency, whereas CO exhibits a negative effect on the COS removal.