This study examines the establishment of Sea-po (서포) in the opening period of Korea at the end of the 19th century. The role they played, the particular situations and their geographical characteristics are researched, The earliest sea-po was Koh-je-hong sea-po, which was established in Tae­kwang-kyo at the end of 1880s. Around 1905, a specialised book distribution system was set up with establishement of Chu-han-yung book store, Kim-sang-man book store, Jesuit book store, Tae-dong su-si, Kae-myung sea-kwan, Tong-wha seo-kwan. The owners of the seo-pos were pioneers in introducing modern culture with nationalistic consciousness, although they were primarily businessmen and their social origins varied. The primary role of seo-pos was selling a variety of books but some combined printing and publication of books as well. It seems that publication business took roots around 1908, though it is difficult to know the accurate dates of first attempts. Some sea-pas offered book rental services for poor people who could not easily afford to purchase books. A certain amount of deposit had to be paid to benefit from the services. Jesuit Bookstore in Pyungyang had a library facility with a large stock or books in the same building open to public for free. These sea-pas started mainly in Seoul and Pyungyang, which were traditional centers for economic and cultural affairs. Early introduction of foreign cultures and commercial developments in these areas contributed to the establishment of sea-pos. The sea-po which took charge of book distribution in the provinces was set up around 1906. One of the important findings of this study is that the geographical distribution of sea-po shows the following three characteristics. First is that the area such as Seoul, Taegu and Chunju were the traditional centers of publishing culture from which Pang­gak-bon(방각본) emerged. Second characteristic is Pyungyang and the surrounding Pyungbuk province, and harbors like Inchon and Pusan, which had the benefits of early spread of modem cultures. Third characteristic is Kaesung and the surrounding Hwanghae province which bridged Pyungyang and Seoul. The reception of foreign cultures stimulated the commercial spirits traditionally attributed to Kaesung to establish sea-pas most actively.