Case records have been scattered in Chinese Classics since it was created by Chun Yuyi in Western Han Dynasty. During Ming and Qing Dynasty, there existed many monographs on case records such as Classified Case Records of Celebrated Physicians，Supplement to Classified Case Records of Celebrated Physicians, etc. There was a famous Chinese physician Zheng Qinan, who reported it was not difficult for a Chinese medical physician to prescribe medication but difficult to differentiate syndromes, and more difficult to distinguish between yin and yang in Essence of Chinese Medical Science. Many modern Chinese physicians have still tried to summarize and hand down their own clinical experiences. The medical record of early stage diabetic cases, which has broken new ground for medical case analysis, has taken distinguishing between Yin and Yang as first and then differentiating Six meridians, where the core is protecting Yang Qi. The theory, principle and prescription of this medical record have been derived from Yellow Emperors, Treatise on Febrile Diseases and other classics.