H2S oxidation by oxygen on catalysts V2O5/Al2O3, V2O5/TiO2, V2O5/Al2O3/TiO2 was studied at temperatures below the sulfur dew point. High activity and the oscillation character of the oxidation were demonstrated by catalysts with low contents of V2O5 (3-5 wt.%). The increase in the V2O5 concentration to 10-20 wt.% results in the reduction of the catalytic activity and oscillation ability. On a pure V2O5 catalyst, the oscillations were trot detected. The difference between the catalysts with the high and low concentrations of V2O5 is explained in terms of the structures of the V5+ species formed in the catalysts.