Results of the investigation of thermocyclic strength of flat corset-type specimens (hour-glass-shape) (Getsov, L. B.et al., Industr. Lab., 1982, 7, 44)* from nine heat resistant alloys on a nickel base with protective coatings: electron-beam, i.e. single-layer system M—Cr—Al—Y, multilayer, dual-layer, diffusion, slurry and plasma spray coatings are represented. It is shown that the service life of electron-beam coatings is considerably higher than that of the pack cementation and slurry alumosilicide coatings. Dual-layer overlay coatings with an external ceramic layer have the optimum characteristics. Regularities are established for microcrack initiation and propagation in coatings and high-temperature alloys, depending upon the technology of the coating's deposition and test conditions.