Abstract: Ti45Al-8Nb-m Y（m =0, 0.1, 0.3 and 0.6at%） alloys were prepared by vacuum arc non-consumable melting method. The influence of Y doping on the microstructure and high temperature hot corrosion resistance of the alloys were studied. The results show that doping of minor Y can not significantly change the main phase composition of Ti Al-Nb alloy,but can effectively refine the microstructure of the alloy and inhibit the formation of defects such as pores in the alloy. The high temperature hot corrosion test reveals that doping of minor Y in Ti Al-Nb alloys effectively improves its high-temperature corrosion resistance. Among the investigated Y concentrations, the alloy with 0.3at% Y exhibits the least severe corrosion product delamination and the most dense corrosion product layer. The improvement can be attributed to the effective refinement of the α₂+γ lamellar microstructure and the increase of the γ phase content by Y doping. These factors facilitate an increase of Al₂O₃content in the corrosion products and promote the formation of a continuous protective Al₂O₃intermediate layer, which inhibits the internal diffusion of corrosive media such as O, S and Cl.