Abstract
The medical text books used during the Joseon Dynasty can be seen to change over time by examining various records. These records show that the list of medical textbooks suddenly changed a lot between the era of King Sejong and Sejo in the Joseon Dynasty. However, since there are not many studies on this topic yet, this study was conducted and the following causes of these changes were identified: The first reason is the compilation project of Euibangyoochui (醫類聚聚) because the date of compilation of Euibangyoochui is clearly related to the period of change to the list of medical textbooks. The second reason is the difficulty of the medical examination during the Joseon Dynasty. Medical tests in the Joseon Dynasty were very difficult. Therefore, it was too unrealistic to keep 25 or 26 textbooks. Third, there was the problem of supply and demand of medical textbooks. Because the prices of these books were very high at that time, owning 25 or 26 medical books for an individual was a significant financial hardship. This study was able to confirm this through various forms of circumstantial evidence. However, more historical materials should be discovered in the future and research should be conducted to more accurately grasp the situation of the time.