The article presents the theoretical analysis and the empirical research on professional high school students’ self-determination as a final link in the chain of life events that determined or annulled formation of their professional identity. The social and professional self-determination of high school students is inextricably linked with acquired life experience, which forms the horizons and determines plans for the future, and their ambivalent social status forms such a professional life perspective, which depends not on their knowledge, skills and talents, but rather on their attitudes to professions and their basic value orientations. A person’s psychological age on the scale of his/her life path received a deep theoretical and empirical substantiation in the works of K. Abulkhanova-Slavskaya, L. Antsiferova, N. Loginova, I. Kon, V. Roments, T. Titarenko, F. Vasilyuk. For experimental studies of the life path, several techniques were created: the psychobiographical method of Z. Freud, the casual-metering of E. Golovakhi and A. Kronik, the psychological autobiography of E. Korzhova, the potential of individual being of I. Manoha. Today, there are many methods to study psychological time on the life path scale. The main problem of these techniques is the lack of a clear data processing algorithm to obtain “visual” results. We consider that the casual-metering is free of this problem: it demands unambiguous answers “yes” or “no”, the results are recorded in the causative matrix and graphically presented in the causogram. It should be noted that high school students’ professional self-determination has not been investigated by this method, and conflicts and transformations concerning decisions on professional choices have not been described. In order to study the influence of socio-psychological factors on transformations of high school students’ professional self-determination, the article describes the full range of social-psychological factors and their causal relationship. Eight areas were identified that affect high school students’ professional choices (socio-political climate, economic status, stereotypes, fashion, inheritance, self-awareness, abilities and talents, values), and the interaction of these areas are analyzed. Socio-psychological factors are considered from the point of view of professional choice reflection in high school students’ consciousness. The analyzed results allows us to conclude that one and the same factor can be destructive, reflective, or affirmative, depending on the causal relations that are characteristic for situations of high school students’ professional choices. Economic reasons and the influence of stereotypes significantly influence on high school students’ refusal from their own professional orientations. Inheritance is one of the most controversial factors in transformations of decisions regarding high school students’ professional definition choices, as it can be a reflective factor when it is a consequence of an inner Self expression, or a destructive factor in the context of a socio-political or economic situation. Thus, we consider it is necessary to study the problem of professional choosing by the casual-metering method of life events, since this approach can reveal the multilayered and interconnected nature of the factors and obtain detailed results for recommendations given to psychologists and career counselors