Ti-Mo-O alloys were used to analyze the effect of Mo and O contents on the mechanical compatibility and biocompatibility.The bending modulus,bending yield strength and springback ratio of the alloys were evaluated by using three-point bending tests and bending load-unloading tests.The biocompatibility was investigated by the adhesion,proliferation and the alkaline phosphatase(ALP)activity of mouse osteoblast-like cells(MC3T3-E1).The results showed that the bending modulus and bending yield strength first were increased and then decreased with the increase in Mo content,while the springback ratio exhibited an opposite trend to the bending modulus.With the increase in O content,the bending modulus remained almost constant,while the bending yield strength was increased.The springback ratio exhibited a similar trend to the bending yield strength.The in vitro biological experiments showed that the Ti-Mo-O alloys had excellent biocompatibility due to the formed stable oxide films on their surface.With the increase in O and Mo contents,the TiO_(2)-MoO_(2)oxide film became denser.Combining with mechanical compatibility and biocompatibility,the Ti-15Mo-0.2O and Ti-15Mo-0.3O alloys were more suitable for the biomedical application of spinal fixation device.