Abstract: In order to study the effect of annealing temperature on the corrosion performance of the alloy, the recrystallization annealing tests of the cold rolled Ti-15 Mo alloy were carried out at 740 ℃, 760 ℃, 780 ℃ and 800 ℃,respectively. The microstructure and electrochemical corrosion behavior were investigated by X-ray diffractometer（XRD）,optical microscope（OM） and electrochemical workstation. The results show that the Ti-15 Mo alloy annealed at 740 ℃ and 760 ℃ is composed of α and β. When the annealing temperature increases to 780 ℃ and 800 ℃, α phase disappears and the alloy consists of single β phase. With the increase of the annealing temperature, the alloy successively undergoes the decrease of fiber texture density, formation of subgrain boundary, recrystallization nucleation, grain growth and formation of equiaxedβ grains. The corrosion resistance of Ti-15 Mo alloy in 3.5%NaCl solution increases first and then decreases with the increase of annealing temperature. The alloy has the highest corrosion resistance when it is annealed at 760 ℃. With the increase of the immersion time, the corrosion resistance of the alloy is significantly improved. After immersion for 21 d, the alloy exhibits excellent corrosion resistance due to formation of the compact and stable passivation film on its surface.