Abstract: A new elastic-plastic model for prediction of fatigue crack growth under varable amplitude loading is presented in this paper.The cyclic J-integral, J, is used as described parameter in the model.The model takes into account"retardation effect" caused by tensile overloads and "acceleration effect" caused by compression load cycle. What is more, it takes into account plastic effects on crack growth. The predicted lifes by using this model under spectrum loading are in good agreement with experimental data.