The general development situations of aero-engine heat strong titanium alloy(or high temperature titanium alloy)BT25 in the former Soviet Union are introduced;The composition characteristics and advantage of the reinforcement in heat treatment of BT25 alloy,and etc.,are further elaborated;Physical properties under annealing state and various mechanical properties of BT25 alloy have been given,upon explaining the relationship between heat strong titanium alloy microstructure and its mechanical property.