The purpose of this paper is to review and to discuss the effects of the medical books compiled and published in the late Koryŏ Dynasty and the early Chosŏn Dynasty. A wider and deeper study of the Korean native medicinal stuff gained momentum beginning from the late Koryŏ Dynasty, resulting in the publication of various medical books on the local medicinal stuff in the early Chosŏn Dynasty. In particular, King Sejong, King Sejo and King Sŏngjong, who had a keen interest in the medical field, made a great deal of efforts to enhance the medical art through the improvement of medical system and education in the country. Consequently, an excellent medical book entitled "Hyang Yak Chip Sŏng Bang" was published in the King Sejong period, and later another famous medical book of "Ŭi Pang Yu Ch'ui", a comprehensive compilation of oriental medical arts, was published. The compilation of the above-mentioned two books on medicine was known as one of the outstanding academic achievements of the Korean medical science at that time. These academic achievements laid the foundation of the famous medical book, "Tong Ŭi Po Gam", compiled by Hŏ Chun. Moreover, every effort was made for the medical development in the periods of King Sejo and King Sŏngjong through the publication of new medical books and the Chinese books on medicine in the Myŏng period of China. The medical book, "Ŭi Pang Yu Ch'ui", in particular, has been recognized as one of the invaluable cultural assets not only in terms of its quantity but also in its quality. To recapitulate, the compilation and the publication of the medical books in the early Chosŏn Dynasty resulted in paving the way for the independent development of Korean medical science. It is regrettable, however, that the great tradition of such an academic achievement could not be further developed due to the reckless inducement of the Chinese medicine in the Myŏng period of China.