This study reports a field study that examined the citizens’ needs and perceptions of library services at a municipal public library system of Mapo-gu, in an attempt to develop a comprehensive service plan that can satisfy the diverse public needs in the changing social environment. We administered a self-reported questionnaire to 800 library users and 300 non-users in the area to examine their reading habits, library use, and perceptions of library services and programs. As a result of the analysis, 53.7% of Mapo-gu residents used one or two libraries among all 16 municipal libraries, and the primary criterion for selecting the main library was accessibility(63.9%). And only 53.8% of library users had experience participating in the library programs. The respondents also showed strong perception that the library is an essential place for the community and the children. Study results indicate that the library system should further expand the collection size, diversify information contents, improve the physical space including library facilities, and build more libraries. In order to fulfill the role of public libraries as the central place of the community, the municipal city should further invest in enhancing accessibility, spatial innovation, and diversifying service contents and media.