A novel biomedical titanium alloy with the ability to undergo self adjustment in its Young's modulus was developed. In spinal fixation devices, the Young's modulus of the metallic implant rod should be sufficiently high to suppress springback for the surgeon, but should also be sufficiently low to prevent stress shielding for the patient. Therefore, deformation-induced ? phase transformation was introduced into β-type titanium alloys so that the Young's modulus of only the deformed part would increase during operation, while that of the non-deformed part would remain low. The increase in the Young's modulus due to cold rolling was investigated for a binary Ti-12Cr alloy (mass%). Microstructural observation and Young's modulus measurement reveal that the Ti-12Cr alloy undergoes deformation-induced ? phase transformation and exhibits the increase in the Young's modulus by deformation.