The low cycle fatigue behavior and fatigue crack growth rate (da/ dN) of alloyIN718 were studied in detail at the temperature of 360℃, 550℃ and 650℃, including thelow cycle fatigue (△ε / 2)-2N_f curves, cyclic stress-strain behavior, Massing effect, theLCF lives expressed by plastic strain energy and crack growth rates. The effect of holdtime on (da / dN ) was also discussed. The experimental results show that this alloy appearscyclic softening at various temperatures and has Massing characteristic at the testtemperatures. The relationship between plastic strain energy and fatigue life of alloyIN718 is linear on double logarithm coordinate. From 360℃ to 550℃ , the change of(da / dN) of alloy 718 is slight, but the (da / dN) at 650℃ is much higher than that at550℃. The effect of hold time on (da / dN) is obvious at 650℃, and the (da / dN) can becalculated by Eq.(8) in this paper. The low cycle fatigue behavior and the fatigue crack growth rate (da / dN) of alloy IN718 were studied in detail at the temperature of 360 ° C, 550 ° C and 650 ° C, including the low cycle fatigue (Δε / 2) -2N_f curves, cyclic stress The effect of holdtime on (da / dN) was also discussed. The experimental results show that this alloy appears in cyclic softening at various temperatures and has Massing characteristic at The relationship between plastic strain energy and fatigue life of alloy IN718 is linear on double logarithm coordinate. From 360 ° C to 550 ° C, the change of (da / dN) of alloy 718 is slight, but the (da / dN) at 650 ° C is much higher than that at 550 ° C. The effect of hold time on (da / dN) is obvious at 650 ° C, and (da / dN) can becalculated by Eq. (8) in this paper.