Comparative studies of the tribological properties of solid lubricant coatings of three main types (MoS2, a-C(H)) and Mo-S-C-H in an inert gas medium have been carried out. It has been established that the coefficient of friction for the Mo-S-C-H nanocomposite coating is somewhat higher than for the other two. And its wear resistance is comparable to a-C(H) and higher than that of MoS2. The friction coefficient of the Mo-S-C-H coating was determined by the nature of tribo-induced surface modification. It included the formation of a nanofilm with a thickness of 6 nm and layered atomic packing characteristic of the MoS2 phase and graphitization of the a-C(H) nanophase, which was accumulated in wear debris. Keywords: nanocomposites, molybdenum disulfide, amorphous carbon, solid lubricant coatings, tribological properties.