Abstract: Low-cycle fatigue characteristics of 10Ni5CrMoV steel were investigated under different strain amplitudes. The characteristics of cyclic stress-strain response, hysteretic loops, cyclic property, cyclic plastic strain energy density of the steel were investigated and the low cycle fatigue life was predicted. The fracture morphologies under different strain amplitudes were analyzed by SEM. The results show that the 10Ni5CrMoV steel exhibits cyclic softening property when the total strain amplitude is greater than 0.4%. The stabilized hysteretic loop is getting wider with the increase of strain amplitude. The relationship of cyclic plastic strain energy density and strain amplitude is approximately linear. The low-cycle fatigue life of 10Ni5CrMoV steel meets the Mansion-Coffin model relationship. The Halford model based on cyclic plastic strain energy density is an effective model to predict the fatigue life. Fatigue cracks initiate from the surface of the specimen, the fracture zone exhibits typical dimple fracture pattern