Abstract:effects of annealing temperatures (Ta) on microstructure and tensile behavior of Ti-50.8Ni-0.3Cr (at%) low-temperature superelastic alloy were investigated by optical microscopy and tensile tests. The results show that, the microstructure of the as-received alloy is fibriform, and the recovery and the recrystallization occur in the alloy during annealing. When Ta =350-500 oC, the alloy is at the recovery stage, and the microstructure is fibriform. When Ta =550-590 oC, the alloy is at the recrystallization stage, the microstructure turns to the unstrained equiaxed grains, and the recrystallization temperature of the alloy is about 570 oC. when Ta =600-800 oC, the alloy is at the grain growth stage, the microstructure shows larger and asymmetrical grains. Ta also strongly influences the tensile behavior of the alloy at low temperature (8 oC). With increasing of Ta, the critical stress of the stress-induced martensitic transformation declines at first and then rises; the work hardening ability and the tensile strength of the alloy annealed at 350-500 oC are higher than those of the alloy annealed at 550-700 oC, but the elongation of the latter is significantly larger than that of the former. When Ta >650 oC, the elongation of the alloy decreases due to the grain growth.