The interrelationship of the corrosion activity of enamel melts containing a complex adhesion activator, their specific electric conductivity, and the strength of the adhesion of the corresponding coatings is investigated. The partial and integral effects of aliovalent oxides on the properties of prime vitreous enamels are determined. The principles of the electrochemical theory of adhesion of enamel coatings on steel, using a complex adhesion activator, are confirmed.