The purpose of the article is to present the results of the study of loneliness factors, in particular the factors of educational socialization, which influence the experience of loneliness in adolescence. The study involved 272 people aged 14–16 years (149 boys and 123 girls) and used «Differential questionnaire of loneliness» (E. Osin, D. Leontiev), «Test of vitality» (S. Muddy), the method of «Emotional self-awareness» (O. Vlasova, M. Berezyuk), Dembo-Rubinstein method, author's questionnaire. 58,1% of the studied adolescents are characterized by a low overall level of loneliness. In 38% of respondents this figure is average, and in 4% of adolescents – high. The inability to stay alone was indicated by 20,2% of respondents, 72,1% of adolescents have an average level of dependence on communication. The average level of ability to find a resource in solitude was found in 57% of adolescents, high inherent in 9,6% of subjects. 33,5% of subjects showed low development of positive loneliness. The study identified the following age characteristics of loneliness: at 14 years of age expressed a negative attitude towards loneliness, which becomes less pronounced at 15 years and continues to decline at 16 years; in 15–16 years the degree of acceptance of loneliness and solitude increases, the ability to constructive use of solitude develops. It is statistically established that there are relationships between indicators of adolescent loneliness and components of their educational socialization: educational (dissatisfaction with education, learning conditions and content of educational activities), interaction (dissatisfaction with relationships with friends and classmates, including the end of friendships), environmental (dissatisfaction with vacations, leisure) and psychological and educational (dissatisfaction with their own lifestyle in the absence of psychological assistance). It was also found that the experience of loneliness in adolescents is due to the influence of such individual differences as low levels of resilience, self-esteem, low levels of empathy, the ability to express emotions, taking responsibility for their own emotional experiences.