The article addressed issues related to treatment in the literature of the essence, content, typology of the phenomenon of “transition”. It is noted that transition characteristics configure antagonism between the previous totalitarian and the new democratic regime. It also considers the two interpretations of the notion of transition – as a transition from a totalitarian to a democratic system that occurred in the states of Southern Europe and Latin America, and secondly – as a process of changes of a society which was organized on socialist socioeconomic model into a society based on democratic values and a capitalist socioeconomic model that operates on market economy principles, which emerged after the fall of communism in the countries of Central and Eastern Europe and of the former USSR. While treating the problems which countries that have started radical social transformation and democratic transition faced or are facing, the article attempts to distinguish the modernization theory and transitlogy and to substantiate a new concept of completed democratic transition, which represents the stage of creation in these states of a democratic regime and the end of the transition process.