Since the early twentieth century, there has been strong opposition to Chinese medicine within Chinese society. Critics have attacked Chinese medicine as unscientific and a hindrance to the development of the nation. I argue that doctors of Chinese medicine have responded to this charge by developing a "postcolonial" form of medicine that is based on the celebrated methodology of "pattern recognition and treatment determination bianzheng lunzhi [image omitted]." I show that bianzheng lunzhi plays two contradictory roles in everyday clinical practice, distinguishing the uniqueness of Chinese medicine from biomedicine while providing a technology for integrating these two medical practices. Through the close examination of a typical medical case, I show how these dual processes of purification and hybridization have become the central dynamic in the postcolonial transformation of Chinese medicine.