This study investigates the self-concept as a factor of professional growth of a psychologist. The profession for a human is a source of livelihood and a means of personal fulfillment. At the present stage of social and economic development it is an important problem of training a future psychologist, providing his / her formation as an active actor and it requires, firstly, proper training, and secondly, a great responsibility for the results of his / her professional activities. The professional choice and professional orientation of the personality occur due to personal components of the professional activity, the development of which is influenced by a number of factors, among which the dominant one is the self-concept. This phenomenon of the professional formation determines the complexity of the dynamics of the individual professional growth, especially if a human makes his / her choice of profession in adulthood, having one higher education. The results of the empirical studies have confirmed the assumption of the existence of significant correlations between motivation and performance of the self-actualization, namely values, creativity, contact, autonomy and self-understanding. Also there were positive correlations found between the index of achievement motivation and performance of the life-purpose orientations in respondents of humanitarian and technical directions: the purpose of life and the locus of control. It is found that the rate of achievement motivation constitutes a significant correlation with indicators of personality traits. In particular, the positive associations are revealed with indicators of sociability, insight, empathy, tolerance, and social activity; negative connections are stated in the indicator of achievement motivation with indicators of guilt, cool, carefree, spontaneous aggression, trait anxiety, irritability, and shyness. Qualitative and quantitative analyses of the study showed the presence of positive correlations between achievement motivation and performance components of the self-concept, which confirmed our assumption of the self-concept as a dominant factor of professional growth of a psychologist.