The study presents innovative interpretation of human socialization as a system of processes of social adaptation, autonomization and support of personal development. It gives theoretical substantiation of the concept of triune socialization, uncovers its opportunities for solving the problem of continuity of education and upbringing, social and personal development. According to the concept of triune socialization, support is viewed as a purposeful process; unlike upbringing, this process is entirely built upon educatee’s subjectness.