Nowadays social media have been widely used in daily life to provide social network services. Library and information services should also be adjusted in accordance with users' changing information behavior and should develop innovative services and policies. This paper first outlines the concept and development of social media, and introduces a couple of examples of foreign applications of social media to library and information services. Next, this study explores the possible challenges of combining social media into library services in Taiwan. Finally, this paper proposes that domestic library and information services should enhance integration of policies and education in information literacy for librarians. Via social media, libraries may also establish sustainable relations with users.