This study presents the results of investigation of the wear resistance of the electrospark coatings on the specimens, which are manufactured from the material of a barrel and piston rings of a D-100 locomotive engine for the purpose of determining the conditions of improving their working efficiency.   The application of the method of electrospark alloying (ESA) was based on the possibility of nanostructuring the surface layers and forming multicomponent compositions in them. Nanostructuring is the most efficient method for the surface strengthening, which ensures the maximal uniform distribution of stresses and deformation at the boundary surface layer--substrate, and the multicomponent compositions make it possible to create the constructions that consist of a strengthening phase, which hardens the surface layer, and a soft antifriction phase that ensures the low coefficient of friction. Using these possibilities of the ESA and considering high loads and temperature conditions of the work of the friction couple barrel--piston rings, the choice of the alloying materials of the coatings was based on the requirements of high strength, heat and wear resistance of the surfaces of those workpieces. In this context, a VK-8 metal-ceramic hard alloy, chromium, molybdenum, VBr-5M bronze, and the materials with high antifriction properties such as lead, copper, graphite, molybdenum disulfide (MoS₂) based on epoxide, a D16T aluminum alloy, (MoS₂ + Mo) were chosen as the electrode materials for the formation of the coatings.  Tests for the score resistance were carried out using an SMTs-2 friction machine in an oil bath according to the scheme roller--pad by the method of a steplike loading in the range of loads 20-220 kg/cm². The roller was manufactured from the material of a barre; the pad was cut out of the material of the ring. Electrospark coatings were performed using an Elitron-22 device. Power parameters of the ESA were selected taking into account the formation of finely dispersed nanocrystalline structure, whose conditions of manufacturing were determined in previous works. The tests for wear were also performed using an SMTs-2 device at a load of 100 kg, the rate of rotation of the specimen of 500 rot./min. for 20 h.  The results of the investigations showed that the specimens with the electrospark coatings made of molybdenum plus molybdenum disulfide based on epoxide and VBr-5M bronze plus MoS₂ based on epoxide had the lowest coefficient of friction and the best score resistance. The coefficient of friction of the above coatings is about 2 times less than that of the couple made of the initial materials at a load of 70 kg/cm² which is characteristic for the friction couple barrel--piston rings. The tests for wear showed a more significant efficiency of the application of ESA for manufacturing the antifriction coatings on the rings than on the barrel.