The purpose of this research is to propose the mediumand long term plan for the development of new branch libraries of the National Library of Korea. As the most appropriate strategic direction of planning the branches, proposed is the "bipolar and multidirectional" model which means the establishment of the only one branch library of the National Library of Korea and then, if necessary, more than one national libraries later. In this research, it is suggested that the National Library of Korea as a national library take a leading role for the development of nationwide library system, develop a sustainable medium- and long-term plan for securing the appropriate budget, human resources, and legal support, and help all kinds of libraries improve the level of services.