Abstract: Purposeful formation of any quality in children in the course of educational activity always requests from teacher to solve the problem of essential pre-determining features of this quality. The lack of essential properties impedes process systematically organization and criteria selection for this quality formation. So person's personality lacks an established, generally accepted definition. Therefore, this study uses the basis of activity approach developed in the researches by A.N. Leontiev. It is shown that the activity approach is significantly different from all other approaches due to the fact that it discloses the ways of personality forming while the known methods aim to discover and use already existing human qualities. Participation in the social activities is the condition for the formation of human personality. Personality is a hierarchic system of personal meanings. Characteristics of a person are properties of this system. The real basis of human personality is the sum of his public relations to the world realized through the totality of his activities. There are two types of activities hierarchy, respectively typical for individual and personality. Hierarchical relationships of separate activities of individuals and personalities are formed in different ways. In the composition and activities of the individual and their relationship is directly determined by the properties of the subject-innate, acquired-and depend on the current state of the body needs. Hierarchical activities relations characterizing the personality are "separated" from the states of organism; activities hierarchy is generated by own development and form the core of a personality; activity ligaments are formed in the system of relations which the subject enters. Formation of student’s personality is the result of his participation in the system of social relations.