笔谈是明清东亚（中、朝、日）文化交流的一种特殊方式，也是当时东亚地区的药物知识交流的一个重要途径。医学虽不是笔谈的重点，但笔谈时涉及的医学内容以及专门的医家笔谈文献，反映了药物知识的传播途径与过程。我们以明清时期东亚笔谈为中心，勾勒笔谈中有关药物知识交流的情形，梳理东亚药物知识的内部流通及其与外部接触，可以进一步认识东亚医学知识的环流与多层建构。东亚笔谈对药物的讨论大致分为三个阶段，笔谈中有关药物知识的交流并非一条单向性的单一直线，也不是东亚三地相互的三条并行线，而是多层次的、相互交错夹杂的。在全球史的视野下来考察作为东亚地方医药知识的内部环流与外部的接触是十分有必要的。这样的考察对欧亚的医学交流史研究也是很有裨益的。

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.