In the article theoretical and methodological grounds of the “power-property” concept and its implementation in the research of socio-economic formations - ancient eastern societies, Middle-age, Soviet and contemporary Russia - are analyzed. The author intends to show the fallacy of the rejection (which is inherent for this position) of the methodology based on materialistic interpretation of social phenomena. The fruitfulness of the explanation of economic formation of society and the system of property, based on the specificity of the mode of production, not on the authorities of power, is demonstrated. The discrepancy of the “power-property” concept with the facts, characterizing economic formation of ancient eastern society and Middle-age Russia is shown, and wrongfulness of approximation of the economic system of socialism with that of “Asian mode of production” is explained.