The influence of Zr additions on the properties of NiTi shape memory alloys (SMAs) is investigated in this paper. It is shown that the transformation temperatures of Ni50.6Ti49.4-XZrX (X= 0, 1, 2, 3 at %) alloys decrease first and then increase with the addition of Zr. Through the study of mechanical properties and shape memory properties, it reveals that they all increase with increasing Zr content. The brittleness of Ni50.6Ti46.4Zr3 alloy is also discussed. The addition of Zr causes the appearance of the (Ti,Zr)(2)Ni and the NiTiZr ternary phase in Ni50.6Ti46.4Zr3 alloy. The (Ti,Zr)(2)Ni precipitates and NiTiZr ternary phase may lead to the fracture of Ni50.6Ti46.4Zr3 alloy during the heat working process.