The textbook outlines the main provisions of one of the sections of developmental psychology - psychology of primary school age: patterns, prerequisites and factors of mental development of primary schoolchildren - features of various types of activities, cognitive processes, various spheres of personality and mental new formations; the problems of psychological support for the development of younger schoolchildren are characterized; practical tasks and psychodiagnostic techniques are provided that can be used to study the characteristics of the mental development of a child of primary school age. The manual complies with the Federal State Educational Standard of Higher Professional Education of the third generation. For undergraduate students in the areas of “Psychology” and “Psychological-pedagogical education”, it may also be useful to other specialists - teachers, psychologists, psychology teachers, and anyone interested in issues of developmental psychology.