L12-type Al65.5Ti24.4Cr10.1 alloys were prepared by induction melting followed by thermomechanical treatment. Corrosion tests were performed between 1173 and 1373 K in a flowing Ar-1% SO2 atmosphere for up to 150 hr. The corrosion proceeded mainly via the oxidation reaction. The oxide scale was primarily composed of Al2O3, together with a small amount of TiO2 that appeared mainly in the lower part of the oxide scale during the latter stages of corrosion. The formation of the highly stoichiometric, slowly growing alumina scale on the surface significantly improved the corrosion resistance of the alloys. Neither internal corrosion products nor sulfides were detected.