Abstract:The superplasticity of Ti–4.5Al–3V–2Fe–2Mo alloy (SP700 alloy) was studied by the methods of maxium m value and constant rate under the conditions of 755~785℃ , 0.1~0.005s–1 and different tensile axis direction. Typical parts were formed and RT properties after superplastic forming were evaluated. The results showed SP700 alloy has excellent low temperature superplasticity with 3110% elongation at 775℃ and 45° direction with max m value tensile method. The capacity of anti-neck-shrink increased due to strain induced grains growing. The cone shape part formed at 755℃ with the highest height of 100mm under bidirectional pull stress condition, and microstructure has no significant change. RT properties of the sample with 33% deformation are 1027MPa ultrastrength and 16.8% elongation, which are little higher than those of undeformed specimens.