To develop an easily regenerable high-temperature desulfurization sorbent, the oxidation of spent Fe2O3 and CuO sorbents in the presence of O-2 and H2O was studied. The effect of H2O on the oxidation of the spent Fe2O3 and CuO was examined using a temperature-programmed reduction technique and isotopic (H2O)-O-18. In this study, it was found that H2O directly contributed to the oxidation of the spent metal oxides in the presence of O-2. The oxidation of the spent metal oxides (containing metal sulfide MexSy) in the presence of 10% H2O and 10% O-2 could be explained by the following two reactions: MexSy + (z + 2y)H2O double left right arrow MexOz + SO2 + (z + y)H-2 and (z + 2y)H-2 + {(z + 2y)/2}O-2 double right arrow (z + 2y)H2O.