The article is devoted to the peculiarities of socialisation of schoolchildren in closed educational institutions. In the first part of the work, the author considered the essence of socialisation and shown the two-directional nature of this process. On the material of the stages of socialisation proposed by E Erickson, the author demonstrated the importance of adolescence and early adulthood transition. Next, the author presented the mechanisms of assimilation of social experience, the most important of which are imitation, identification, observation and appropriation. The author described the criteria for successful socialisation for boarding school students, the key of which is the manifestation of activity and the ability to create. The combination of the roles of teachers in boarding schools is shown. In the second part of the work, on the example of the Smolny Institute of Noble Maidens, the author studied the conditions contributing to the humanisation of the educational process and the development of subjectivity in pupils. Finally, the author concluded that socialisation’s preferred model ought to combine training, upbringing, and pedagogical participation for each child.