1. A model of fatigue crack propagation was proposed; the model is based on determining the specific energy of inelastic strain cumulated at the distance X* from the crack tip, with an allowance made for the energy irreversibly scattered within the scope of the zone of damageRm (Rm≥X*). 2. The model was tested on a number of structural alloys in various load cycle asymmetries. The calculated and experimental dependences of the rate of fatigue crack propagation on the stress intensity factor were in satisfactory agreement.