In this paper we consider main factors which have an influence on energy efficiency of the cathodic protection and analyze them. Cathodic protection is defined as the ratio of the electrical conductivity of electrolyte, which surrounds the underground (underwater) metal construction (pipeline) and its polarization resistance. The obtained results are correct first of all for the case of presence of modern qualitative insulation, which possess high dielectric properties and is made of, for example, polymers or its’ composition and is meant to be used for protection against electrochemical corrosion of the underground pipelines