The low modulus β type titanium alloy, Ti-29Nb-13Ta-4.6Zr, was designed, and then the practical level ingot of the alloy was successfully fabricated by Levicast method. The mechanical and biological compatibilities, and super elastic behavior of the alloys were investigated in this study. The mechanical performance of tensile properties and fatigue strength of the alloy are equal to or greater than those of conventional biomedical Ti-6Al-4V ELI. Young's modulus of the alloy is much lower than that of Ti-6Al-4V ELI, and increases with the precipitation of α phase or ω phase in the β matrix phase. The compatibility of the alloy with bone is excellent. Low modulus of the alloy is effective to enhance the healing of bone fracture and remodeling of bone. Super elastic behavior is observed in Ti-29Nb-13Ta-4.6Zr conducted with short time solution treatment after heavy cold working. Total elastic strain in that case is around 2.8 %. The mechanism of the super elastic behavior of Ti-29Nb-13Ta-4.6Zr is still unclear.