Chao Yuanfang (AD 550-630) was a renowned medical scientist in the Sui Dynasty.

In Daye Period of the Sui Dynasty (AD 605-617), Chao Yuanfang was appointed as the Academician of Imperial Medical Academy, and later promoted as Court Physician. He was recognized for his abundant practical experience and profound accomplishments in theories of medicine.

In the sixth year during Daye Period (AD 610), Chao Yuanfang was ordered by the emperor to compile Zhu Bing Yuan Hou Lun (General Treatise on the Etiology and Symptomology of Diseases). Consisting of 50 volumes, the book lists 1739 entries of symptoms which break down into 67 categories. With rich content, it summarizes the medical experience since the Wei and Jin Dynasties, and provides a relatively early and detailed record as to the observation and knowledge of diseases. Without prescriptions, the book solely addresses etiology and symptomology. On the one hand, it elaborates on the causes of varied diseases and the importance of examining nine parts of a human body. On the other hand, it also provides a detailed account of the causes and symptoms of various diseases, including medical, surgical, gynecologic, pediatric, ophthalmological and otorhinolaryngologic diseases. The book has been acknowledged as a very precious document among the heritage of Chinese medicine.