Abstract: The conversation by writing was a special way of cultural communication and also an important way to exchange medical knowledge in East Asia, including China, Korea and Japan. Although medical science was not a major topic in the conversation by writing, the medical content included in the conversations and especially the records between professional doctors reflect the transmission path and process of medical knowledge. Focusing on the conversation by writing in East Asia in the Ming and Qing Dynasties, this paper analyses the circulation and multi-construction of medical knowledge in East Asia by examining the spreading of medical knowledge and outlining the paths of internal spreading and external interaction of medical knowledge. The discussion about medicine in the conversation by writing in East Asia can be roughly divided into three stages. The exchange of medical knowledge was neither in a linear process nor in three parallel lines among China, Korea and Japan, but in a multi-layer and mutually mingled style. It is necessary to examine the internal circulation and external communication of medical knowledge in East Asia from the perspective of a global history. This kind of examination is also conducive to the research of the history of medical communication between Asia and Europe.

Key words: conversation by writing, East Asia in the Ming and Qing Dynasties, medical knowledge, circulation and interaction