‘One Book, One City' reading campaign is one of the major reading campaigns, successfully conducted by public libraries in this century. The purpose of this study is to evaluate the significance of ‘One Book, One City' reading campaign, as an innovative, continuing, and collective reading campaign by analyzing its growth and diffusion during the past six years. Also, analyzed are the themes, genres, and publication dates of the books and the characteristics of authors selected for ‘One Book' in order to understand the cultural, social, and community-wide trend and objectives of ‘One Book, One City' reading campaigns. An analysis of lists of ‘One Book, One City' Reading Promotions Projects' available from the website of the Library of Congress, the Center for the Books, and bibliographic records of ninety books from LC OPAC, shows the preference for books recently published, significance of biographies and biographical fictions, and focus on the themes which help people better understand a multi-cultural and multi-racial society.