這篇論文旨在透過中國傳統醫籍，探討廿世紀以前論者如何分類乳癰的名候、解釋其成因、建議其治法，藉以說明左右中國傳統醫學知識變遷的若干動力。研究發現，在廿世紀初以前，中國傳統的乳癰證治論述大概曾經歷了兩次重要的變遷，一次是在六、七世紀前後，其主要內容是既有醫籍中肝脈與情志在身體中的角色受到重新調整;一次是在十三、十四世紀前後，其主要內容是女人作為人母、人婦與人媳的家內角色及其人際關係成為左右其胸乳健康的新條件。整體來說，乳癰證治論述在傳統時期的變遷，與其說是臨床經驗不斷更新的產物，也許更像是傳統論者為了完善說理，而不斷以既有文本呈現的元素為基礎，嘗試重組舊關係、建構新聯繫，進行再發明的結果。也可以這麼說，仰賴文本、崇右典籍和自由詮釋的行為偏好，在傳統論者分類名候、解釋病因和建議治法時曾扮演舉足輕重的角色。這一現象也多少說明，透過醫籍反映的中國傳統醫學，與其說是實驗醫學，也許更接近是以文本詮釋為核心的醫學。 Before the twentieth century, ruyong（乳癰, breast abscesses） was taken as a typical and well-known term, frequently used by medical practitioners or writers of medical literatures, to represent the female breast disease in traditional China. However, since the 1950s, this term vanquished and soon was replaced by western medical terms such as acute mastitis, breast tuberculosis, breast cancer, or breast neoplasm. This article takes traditional propositions about the symptoms, causes and herapeutic methods of ruyong as phenomenal cases to explain why the term survived and persisted for two thousand years and how it was interpreted by traditional medical practitioners or writers. Analysis of this article shows that traditional Chinese medicine is a type of medicine made of texts rather than clinical experiences. Those changes in propositions related to ruyong should be considered more as rearrangement of factors which already existed or reinvention of those connection which did not exist beforehand, rather than objective discoveries from medical practice. If we cannot recognize those traditional characteristics which took medical texts or medical cannons as the supreme authority and resource as well as the ultimate tools to justify and interpret what they found in clinical practice, it will be hard to understand why traditional Chinese medicine as well as those traditional propositions about ruyong changed in such a way in the last two thousand years.