Introduction. Joint activity in child-parent relations contains a significant and poorly studied resource for the development of a younger student's personality. Unfavorable trends in the personal development of a younger student at the final stage of primary general education, such as a decrease in motivation for learning and self-esteem, increased anxiety, and social deficits significantly affect academic success, which determines the relevance and relevance of solving this problem. The purpose of the article is to present the results of scientific and theoretical substantiation and experimental approbation of the program of psychological and pedagogical support of joint activities in child-parent relations with a younger student as a factor in the development of his personality.Materials and Methods. The study involved 99 primary school students aged 10-11 years, studying in the fourth grade (50 boys and 49 girls), as well as their parents aged 29 to 53 years (80 mothers and 19 fathers). As diagnostic tools, the following methods were used: the method of studying educational motivation by M. V. Matyukhina (modification by N. C. Badmaeva); the method of assessing school motivation by N. G. Luskanova; the scale of personal anxiety by A. M. Parishioners (form "A"); the method of measuring self-esteem by T. V. Dembo and S. V. Rubinstein (modification by A. M. Parishioners); methodology of sociometry by J. Moreno (modification by V. R. Schmidt); questionnaire for studying the structure of subjectivity by E. N. Volkova and I. A. Seregina (modification by M. A. Pyzhyanova).Results. The article summarizes domestic and foreign studies on the problem of joint activity in child-parent relations as a factor in the development of a younger student's personality. The scientific and theoretical foundations, goals, objectives, content and stages of implementation, programs of psychological and pedagogical support for joint activities in child-parent relations with a younger student are determined. The results of the approbation of the author's program are obtained, indicating the optimization of the development of the main personal spheres of a younger student: motivational, emotional, spheres of self-awareness and subjectivity of personality.Discussion and Conclusions. As a result of the testing of the program, patterns of dynamics of indicators of the main personal spheres of a younger student in the conditions of psychological and pedagogical support of joint activities in child-parent relations with a younger student were revealed. The analysis made it possible to reveal the mechanisms of the influence of parental interaction in the process of positive joint activity with a child on the development of his personality.