The purpose of this study is to clarify the spatial characteristics of the children's library and user's behavioral characteristics and to empirically analyze the difference in preference of the spatial characteristics based on the using behaviors. For doing this, this study selected 16 children's libraries in the country as a sampling institute and collected and analyzed 661 questionnaires targeting infants, and the lower and upper graders. The results of analysis are as follows. First, while there was a difference in the relation between the spatial characteristics and the user's characteristics according to ages and sexes, there was no difference in the developing stage. Second, there was a difference in the relation between the spatial characteristics and the using behaviors. Detailed results are as follows. While users who visit the library for reading prefer amenity and peacefulness, those who visit the library for other reasons prefer communication and territoriality. Children prefer diversity, peacefulness and communication when they visit in group rather than to visit individually. In terms of behavioral patterns, users who act quietly prefer diversity than those who act actively. Reading use frequency, as the number of times to visit increased, preference on esthetic sense, dynamics, flexibility, leisure, communication and territoriality increased, but preference on safety decreased. As the length of visit became longer, preference on diversity, self-esteem, peacefulness, dynamics and flexibility increased.