Dosan Manase was a famous Japanese doctor in the Muromachi era and was in the vanguard of the Goseiha school of Sino-Japanese traditional medicine. In his "Shinmyakukudenshu" we found an interesting account to explain the meaning of the word "Toryu", which was often found in the medical books written in Dosan's early years. This word signifies "our school" in a general sense, but in this book Dosan used it with the additional meaning of his medical thought originating in Zhu dan xi who was a famous Chinese doctor in the Yuan age. In addition, he mentioned in the same book that Toryu was introduced from China into Japan by Dodo, succeeded by Sanki and propagated by himself. Moreover our extensive investigation of other medical literature showed that Dosan, in his early years, tried to develop a system of medical thought on the basis of that of Zhu dan xi. This is worthy of note because it differs considerably from the stance adopted in Dosan's later years : while he valued Zhu dan xi, he referred to many medical books by various authors, and tried not to favour any particular school.