Abstract: The low cycle fatigue properties of 0Cr15Ni70Ti3AlNb(X-750)nickel-based alloy materials for reactor spring under aging hardening condition from room temperature to 650 ℃were studied.Manson-Coffin and Zheng Xiulin constitutive equations were used to calculate and analyze the fatigue performance data.The results show that, compared with the M-C classical relational expression, under the conditions of room temperature, 350 ℃, 500 ℃and 650 ℃, the Zheng Xiulin relational expression obtains higher fitting consistency.The predicting precision of the fatigue life of X-750 alloy by using zhengxiulin relation is higher.