This study is to collect and organize the writings and related materials of Lee Jae Wook, the first director of Korea National Library, and, therefore, find out his achievements in the library system. By comparing existing and newly collected lists of Lee’s writings, the total lists had been revised and complemented. As a result, the lists were finalized with 190 writings which were published on books, library journals, cultural magazines and various newspapers. In consequence of analyzing the writing-lists with historical records, Lee’s accomplishments are as follows: First, he find philological and bibliographical value in Korean books and writings by studying classic literature. Second, he played an important role in grafting theory and practice of modern library into Korea in Japanese colonial era. Third, he made an effort to diffuse reading culture all around Korea through column and essays he published. Fourth, he contributed to make status and fundamental of early National Library with pioneering leadership by solving a problem of transferring National Library’s legislation books that U.S. Military Government Office requested and founding Chosun Library School. Fifth, he implemented the core business of environment of Korean Library such as library class, establishment and implementation of Reading Week, foreign cooperation and etc., as a president of Chosun Library Association.