This study drew the planning method of school common use space in the social aspect of exchanges and contacts between adolescents, by considering the characteristics of the adolescent period. In order to achieve the research goal, the study conducted a literature review and an analysis to extract physical decision factors that would promote social interaction between adolescents most actively. The decision factors were then properly applied to each of the spatial characteristics of school common use space, and that helped the study come up with planning methods. The results can be summarized as follows. First, as for the physical decision factors of exterior common use space in which the most active social interaction would occur, the study extracts width (D) of exterior space and height (H) of a building to correspond to the former, a form to surround exterior common use space and others and in terms of physical decision factors of interior common use space, proximity-based space organization, space hierarchy-based addition of placeness, aesthetic and cognitive space organization and others are selected as the relevant factors. Second, the study confirms that proper amount of stay time, forming of internal space sense and others should be considered for exterior common use space planning. Activity exterior space is designed in a form of more than D/H>4 and ㄷ–shaped inclosure when sociality exterior common use space is planned in a form of 1