In our previous study, the reducing power of reactants was the most important factor in the selective oxidation of H2S and the selective oxidation of H2S could be applied to the hot gas cleanup in IGCC system. V2O5 catalyst has been used for the selective oxidation of H2S. However, because the catalyst was reduced to a suboxide after the reaction, its reactivity was not stable. On the other hand, the reduced vanadium oxide, produced by a reduction of V2O5 at 600 ℃ for 24 hours, showed a stable reactivity and an excellent conversion of H2S and selectivity for the elemental sulfur.