Abstract
Eoyakwonbang is a collection of prescriptions of Yuyaoyuan, an imperial medical bureau of China. While the first edition of this book does not exist at present, two versions printed in Korea, and one printed in Japan, which is the well-known Gyesasingan Eoyakwonbang have been passed down. Eoyakwonbang is a meaningful text for the history of medical communication between China, Japan and Korea, but research on the different versions and contents of Eoyakwonbang have been insufficient. Out of the 2 versions published in Korea, Eulheja Eoyakwonbang is different from Gapjinja Eoyakwonbang [another version in Korea] and Gwanjeong Eoyakwonbang of Japan, in that the prescriptions are organized, the ingredients are organized according to the amount of each ingredient for each formula, and the amounts are recorded in an accurate manner. On the other hand, the Gapjinja version has many mistakes in the characters and content. The Gwanjeong version has lesser mistakes in characters, but repeats the content error of the Gapjinja version. Eulheja was printed after correction based on the original version or unknown version from China. Gapjinja was re-printed based on the Gyesasingan version, while Gwanjeong seems to have used the Gapjinja version as its original script, as the mistakes made in the Gapjinja version are repeated in the Gwanjeong version as well.