General issues of cyclic strength of ship structures are covered; standardization of cyclic strength by classification societies and fatigue characteristics of domestic shipbuilding steels. The analysis of characteristic fatigue damages of ship hull assemblies and their causes, as well as the effect of corrosion on the fatigue process intensity are presented. Thermodynamic method of evaluation of fatigue strength of ship structures is considered, criteria of cyclic strength at plane stressed state and bending are obtained, as well as fundamentals of procedure of damage and resource of hull structures at cyclic load are developed.