The possibility of strengthening glass­crystalline coatings with the joint action of three types of modifiers (ZnO, TiO 2 , SnO 2 ) was studied. The influence of the concentration of each out of three modifiers on phase transformations in the process of thermal treatment of the coatings was experimentally examined. A mechanism of the action of oxides­modifiers on the formation and growth of the crystal nuclei of the formed phases was proposed. The mechanism for strengthening a glass matrix consists in intercalation (embedding) of the modifying groups (ZnO and TiO 2 ) into the grid of glass with the subsequent formation of nuclei of a new crystalline phase of the type of solid solutions. The specific character of chemical composition consists in the introduction of SnO 2 to a glass­crystalline coating in the amount of not less than 15 %, which does not activate the process of phase formation but contributes to the inhibition of growth of the crystals of newly formed phases. It is the presence of tin dioxide that offers a possibility of controlled crystallization and obtaining materials with the set submicrostructure. The fine crystalline phases, which are immobilized to a glass matrix, contribute to the formation of homogeneous sitall­like structure. In this case, the proportionality of the particles is achieved, which makes it possible to obtain material with high strength and thermomechanical properties. The new compositions of glass­crystalline coatings with increased (by 50 %) strength and thermal resistance (by 70 %) may find wide application in the technology, different areas of chemical, textile industry, machine building, electrochemistry, medicine and construction.