In this paper an energy-based model for predicting fatigue life and evaluation of progressive damage using plane-stress assumption is proposed. This model allows us to predict fatigue durability taking into account principal directions of the stress tensor relative to planes of elastic symmetry of material. First, the unknown parameters of this model will be calculated for three different composites with various lays-up. Method for determining these parameters is based on the minimum necessary set of experimental data. Afterwards the model was used to predict fatigue life and estimate accumulated fatigue damage in a unidirectional composite under different angles of loading. The analysis of conclusions of the theory for various loading conditions was carried out and performed comparison between the experimental data and predicted results. The predicted fatigue lives obtained by the proposed energy model were in good agreement with the experimental data.