In a study of the antifriction properties of dialkyldithiophosphoric and dialkyldithiocarbamic complexes of molybdenum and zinc in a wide temperature range (25-350 degrees C) it has been shown that molybdenum compounds are more effective than zinc complexes; in this case dithiocarbamic ligands ensure lower friction coefficients than dithiophosphoric ligands. Auger spectrometry has been used to study friction surfaces under load in the presence of lubricants with the addition of molybdenum and zinc complexes. For all the compounds studied the distribution of chemical elements of additives over the depth of the surface layers of the metal has been established. The layer of so-called secondary structures has the determining influence on the antifriction properties. A proportional relationship has been found between the thickness of this layer and the friction coefficient for complexes of different nature.