The dissertation deals with the problem of organization of pedagogical conditions which promote formation of primary pupils' personality though playing activity in children's library. Scientific analysis of works on philosophy, psychology, pedagogy and library management convinces in the necessity of profound study of the process of primary pupils' personality formation though playing activity in the conditions of library and information service of children's libraries. The component structure of personality has been specified, the essence of the notions "personality", "formation of personality", "playing activity" has been defined. The notion "formation of personality" is treated as determined by teaching and brining up social conditions dialectical process of interaction and interaddition of cognitive, emotional, volitional, communicative constituent parts, caused by inner and outer regulation of main activity. The empirical experience of L.Antsyferova, L.Bozhovich, L.Vygotsky, D.Yelconin, G.Kostyuk,O.Leontyev, V.Rybalka, S.Pubinshtein, connected with children's personality development, is being taken into consideration. The thesis has been broaden that playing activity itself is the mean of comprehensive and harmonious development and children's play is outer display of psychologically-physiological and intellectual recourses. The author has scientifically grounded the thesis about effectiveness of correlation of children development in their playing activity. There has been shown the retrospective analyses of the play phenomenon in its historically-pedagogical foreshortening, in the defining of its essence, nature, of interaction of procedure and personal components. The investigation of the process of primary pupils' personality development and personality formation has allowed defining its functional mechanism, concentrating attention at their peculiarities at primary school age. In the research paper such functions of play has been singled out as socially-cultural, communicative, diagnostic, educational, didactic, developing, entertaining, therapeutic, the function of self-actualization and the function of self-correction through play. The specific classification of games has been given: according to the place of holding, type of action, age characteristic, national specific. The experimental process with detailed description of games and playing tasks, used in children's libraries, has been widely shown in the dissertation. Untraditional forms of games, creative children's activity, favourable for real children's opportunities and age playing tasks and situations have been named as perspective for primary pupils' personality formation through playing activity in the library. During the experimental research the pedagogical conditions assuring effectiveness of primary pupils' personality formation through playing forms and means were defined and approved. The componential structure of primary pupils' personality formation was grounded; motivational, emotionally-volitional, communicative, cognitive components were singled out. The criteria for defining of the level of primary pupils' personality formation were worked out. The levels are defined as high, sufficient, average and low. The proposed methods of primary pupils' personality development though playing activity in children's library have allowed getting considerable results. It has been established that the process of primary pupils' personality formation, organized according to the given program, had positive dynamics, which contributed to development of motivational, emotionally-volitional, communicative, cognitive components. Comparative characteristics of the experimental data based on quantitative and qualitative facts of four experimental and four control groups has proved that the program of pedagogical guidance in the process of primary pupils' personality formation, developed in the research, has effective results, that is demonstrating expediency of its introduction into the practice of library service of children's libraries. The approaches, worked out in the dissertation, can be the basis for further research of the subject. The materials and results of the dissertation investigation can be used in the optimization of the children's libraries management, for working out of curriculums, study programs, methodical recommendations, special courses, text books on library management and in the system of training and raising the level of skills of workers of education, culture and art.