Аннотация:The mechanism of vapor-gas deposition and polymerization of vinyltrimethoxysilane (VS) molecules on the surface of magnesium MA20 and aluminum A5154 alloy is investigated. It has been established that when the vapors of VS and water condense on the surface of the alloys, polymer siloxane coatings with high protective properties are formed. It is shown that ethylene glyсol (EG) is an effective polymerization promoter due to the crosslinking of silanol and ethanol groups of atoms into polymer structures on the surface of alloys. The main factors influencing the polymerization rate and protective properties of coatings are determined.