The purpose of this study is to derive differentiation strategy through strategy competition analysis on public libraries in order to enhance the competitiveness and efficiency of libraries. To that end, this study conducted a status analysis, management resources analysis, external and internal environment analysis on four public libraries located in Jung-gu, Incheon to identify the situation of strategy competition, and conducted a competitor analysis, customer segment analysis, and customer value analysis of four public libraries through various library related statistical data, national library operation evaluation data, library user satisfaction surveys, and interview with chief librarian and senior librarians. As the result, this study suggests three differentiation strategies by library. First of all, the four public libraries need to provide customized services targeting different target users within the region. Secondly, public libraries need to develop active library services that directly visit passive users, who are information have-nots, considering geographical accessibility and the composition of the population in the region. Last, public libraries should form a cultural community that cooperate with the local community and develop various programs that reflect the identity of the region.