Abstract: In high temperature atmosphere, titanium will chemically react with oxygen to form a brittle oxide layer on the surface of titanium alloy matrix, which will lead to the degradation of its performance. In order to investigate the oxidation resistance of Ti65 alloy at hot working temperature, the oxidation behaviors of Ti65 alloy oxidized for 0.5~10.0 h oxidation in the temperature range of 700-1 100 ℃ are studied. Through the analysis of oxidation weight gain experiment, XRD, SEM, EDS, EMPA and XPS analysis, it can be seen that the oxidation kinetic curve is in linear and parabolic law, and that the oxidation activation energy Q is 308 kJ/mol. When the temperature is 700-900 ℃, the oxidation layer on the surface of titanium alloy is composed of TiO₂, and the temperature 1 000-1 100 ℃, the oxidation layer is composed of TiO₂ and Al₂O₃. With the increase of temperature and extension of oxidation time, the oxide layer depth increases and the oxide film stripping occurs. In addition to forming the oxide scale layer, the oxidation will penetrates into the matrix, and the internal oxidation layer will come into being. This study provides theory and data references for the optimization of chemical compositions and heat treatment process of the Ti65 alloy.