Ti-8Ta-3Nb has been developed as a new biomaterial. The experimental specimens are as-cast and forged Ti-8Ta-3Nb alloys. Treatment in a solution, ranging from 760 to 960$^{circ}C$ has carried out. The microstructural research has carried out after the solution treatment and the hardness was measured. The specific heat and the length variations of Ti-8Ta-3Nb were also measured. The optimum temperature for the solution heat treatment of Ti-8Ta-3Nb was found to be 880$^{circ}C$. This was based on the mechanical properties and the volume fraction of ${alpha}$ phase and their phases shown from the results of the solution heat treatment. From the results, the ${eta}$ transition temperature of Ti-8Ta-3Nb was found to be between 860$^{circ}C$ and 880$^{circ}C$.