The purposes of this study are to understand the current status of using and adoption of social network services for public libraries in Korea and to propose how to activate social network services for the libraries in the future. For this study, the usage of the social network services by 166 public libraries was investigated. In addition, surveys to 40 library representatives from the libraries were conducted and 198 public library users answered users' survey questionnaires. As methods to activate social network services in pubic libraries, providing education and training for librarians, hiring librarians for the service, and monitoring and educating the library users for participating with diversifying promotion channels for the service were suggested.