The corrosion resistance of Ti–Nb–Sn alloys in the 0.9% NaCl physiological and Hank's solutions with different pH values (2.4, 5.4, 7.4) at 37°C were investigated by means of open circuit potential (OCP), Tafel and anodic polarization techniques. The compositions of the passive films were analysed by X-ray photoelectron spectroscopy (XPS). The OCP was found to stabilize within several hours for Ti–Nb–Sn alloys in the Hank's solution but continued to increase in the 0.9% NaCl solution. Tafel results indicated that the corrosion current densities were in the magnitude of below 1μA/cm 2 . Anodic polarization curves demonstrated a wide passive region. XPS analysis results revealed that the passive film mainly consisted of TiO 2 , Nb 2 O 5 and SnO 2 . These observations suggest that Ti–Nb–Sn alloys have a large potential for biomedical applications.