Abstract: The effect of hot isostatic pressure on the mechanical properties and microstructure of a new high-temperature Ti alloy, ZTi700SR, used in 700℃ environment, is investigated. The results indicate that the microstructure of the as-cast ZTi700SR is widmanstatten structure, which is lamellar α+intergranular β+grain boundary α. After HIP, the lamellar α grows wider. After HIP, the tensile strength decreases lightly, and the elongation increases. The dimple size of the tensile fracture of ZTi700SR after HIP decreases, and the material becomes denser.