A novel biomedical alloy with a changeable Young's modulus was developed in order to satisfy the requirements of both the patients and surgeons in spinal fixation operations. The alloy has not only a low Young's modulus to prevent a stress-shielding effect which benefits patients, but also a high Young's modulus to suppress springback for surgeons. In this study, the chromium and oxygen contents in ternary Ti-Cr-O alloys were optimized for achieving a large changeable Young's modulus with good mechanical properties. The Young's moduli of all the examined alloys increase by cold rolling, attributed to the deformation-induced co-phase transformation. This transformation can be suppressed by oxygen, but enhanced with lower chromium content. Among the examined alloys, the Ti-11Cr-0.2O alloy shows the largest changeable Young's modulus and a high tensile strength with an acceptable elongation in both solution-treated (ST) and cold-rolled (CR) conditions. Therefore, the Ti-11Cr-0.2O alloy, which shows a good balance among a changeable Young's modulus, high tensile strength and good plasticity, is considered to be a potential candidate for spinal fixation applications.