This paper deals with the analysis of the content of Zadar Public Library on social network Facebook. This paper is divided into two parts, theoretical part based on literature and a research. First part describes what social networks are, along with a brief overview of their history and the use of Facebook to which this work has an emphasis on. Work then focuses on the use of social networks in libraries. It explains the purpose of the Web 2.0 tool and the possibilities that social media can offer, which is the user's ability to create their own content and concepts of Library 2.0 and Librarian 2.0. The paper presents examples of good practices, tips from literature on how to best implement social networks in the library, challenges that social networks carry with them in library implementation, and previous research that served as a guide and as a material for comparing the given results. The second part of the paper deals with the research and in this part is presented a method of research, research questions, analysis of results and discussion. The research method used in this paper is data analysis which analyzed the type of content, type of posts, comments and likes on Zadar Public Library Facebook page. The conclusion of this research is that Zadar Public Library has successfully implemented Facebook in its work, which has been recognized by the users whose numbers steadily rise trough the years. The library publishes posts rich in multimedia and successfully links its websites, services and events to Facebook.