As a national library, the National Library of Korea is responsible for collection, provision, and preservation of national knowledge, information, and cultural heritage. This study aims to develop performance indicators as a rational tool to improve management of the National Library of Korea for its continuous growth and development. The performance indicators are based on the BSC(Balanced Scorecard), which is useful for linking the organization’s strategies in response to changes in the library environment with performance measurement. As a result, 4 BSC-based perspectives (① Resources, Access, Infrastructure Perspective, ② Usage Perspective, ③ Efficiency Perspective, ④ Potential and Growth Perspective), 19 key success factors, and 71 performance indicators were developed for the National Library of Korea. Also, differences in perception of performance indicators by ranks and job duties at the National Library of Korea were analyzed.