The background of this study is that it is necessary to investigate how the spatial composition of the children's reading rooms in public libraries, which is an important social space for children, have been changing according to social flow and policies in Korea. Through the study, the purpose is to analyze the spatial characteristics and the visible characteristics of furniture arrangement according to the transition of the children's reading room, and use it as basic data for the transition and trends of the children's reading space. As for the scope and method of the study, 9 children's reading rooms in public libraries with a total floor area of 2,500㎡ or more located in the metropolitan area were selected and sorted into the growth, the diffusion and the post-diffusion period based on the opening time. The spatial composition and furniture arrangement of the children's reading room in each period were studied by area ratio analysis, Visible Integration and Isovist of Visibility Graph Analysis. As a result, the size of the children's reading room tends to increase in proportion to the size of the general reading room and circulation that was previously separated is now connected. Also, It has shown that the more recently opened children's reading rooms, the more diverse the convenience and educational spaces. The children's reading rooms have become more functional and collective offering a diverse range of services and activities. The direction of the arrangement of bookshelves, which affects the management and the atmosphere of the reading space, is parallel or mixed shaped with the visual management as it is closer to the recent period, creating a more manageable and relaxed atmosphere.