In order to improve the hot corrosion resistance of yttria-stabilized zirconia (YSZ), an Al2O3 overlay has been deposited on the surface of YSZ by electron-beam physical vapor deposition. Hot corrosion tests have been performed on the YSZ coatings with and without an Al2O3 overlay in the molten salt mixture (Na2SO4+0-15 Wt% V2O5) at 950 degrees C. The presence Of V2O5 in the molten salt exacerbates degradation of both the monolithic YSZ coating and the composite YSZ/Al2O3 system. The formation of a low-melting Na2O-V2O5-Al2O3 liquid phase is responsible for degradation of the Al2O3 overlay. The Al2O3 overlay acts as a barrier against the infiltration of the molten salt into the YSZ coating during exposure to the molten salt mixture with < 5 wt% vanadate.