Phase transformation and mechanical properties of TLM titanium alloy for orthopaedic implant application were studied. The results show that a small amount of slender α″ phase exists in the β matrix after solution treating and water quenching. The formation of α phase goes through two procedures during the aging treatment from 300 oC to 500 oC, one is β→ω→α, and the other is α″→α. While the micrographs reveal that α″ martensite hinder the nucleation and growth of metastable ω phase. The effect of the phase structures on reducing the elastic modulus is in the order of ω＞α″＞α, and the effect on improving the strength is in the order of ω＞α＞α″, and vice versa for improving the elongation of TLM alloy.