Abstract: The oxidation behaviors of most widely used titanium alloy TC4 was investigated at four different atmosphere temperatures ranging from 850℃ to 1 050℃.The morphology of the oxidation and oxide-rich layer of TC4 was analyzed by OM and SEM.The results indicated that the oxidation layer weight addition per unit surface area of TC4 showed a nearly linear relation to exposed heating time.Oxidation skin of TC4 formed by oxidation at single α phase range of lower temperature 850℃ was completely different that at 950,1 000℃ and 1 050℃.The mean thickness of internal oxidation layer was found strongly depending on oxygen diffusion rate at certain heating temperature and independent of heating time.Moreover,vanadium was found readily being enriched within oxide-rich layer.