The purpose of this study is to examine how the floor heating system is affecting to users in childeren's libraries. This study included the method that extracts the affordance of the floor heating system, after surveyed using behavior in children's libraries and referred to J. J. Gibson's affordance and surface concepts. As the positive affordance, it was grasped that the floor heating system promotes social relationships and affords various surfaces for library using, but also as the negative affordance, that hinders users in the public usings and the behaviors for reference and using. The behaviors of these various characters can be regarded as life behaviors resulted from the sitting life style and the natural using behavior can give to children emotional rest and autonomous reading experience. For the function as the children's library, the learning of sociality in the public building and the various reading space, the space planning of children's library should be done after the positive and negative affordances extracted from this study are reflected. The guidelines for space planning are summarized as the followings: the layout of book furniture, the shoe chest and the space around that, the furniture hight and children's eye level, and the practical using of the table for sitting life style.
