The formation and establishment of the theoretical system of traditional Chinese medicine has gone through a long historical period. Since the Warring States period, the rapid social changes and academic schools have created a favorable social and cultural atmosphere for the formation of the medical theoretical system. At this time, ancient doctors also accelerated the discussion on the mystery of human body and the relationship between man and nature, trying to turn medical experience into theory. On the basis of medical practice and anatomical achievements, they absorbed the essence of hundred schools of thought, founded the theories of zang-xiang, meridians, qi and blood, body fluid and spirit, and created the theory of six evils causing diseases in the process of exploring the relationship between man and nature. At the same time, the theory of qi, yin, yang and five elements in ancient philosophy is introduced into the medical field as a methodology to explain human physiology and pathology and guide disease diagnosis and prevention. The theoretical system of traditional Chinese medicine was established here.
The period from Warring States to Qin and Han Dynasties is the formation period of the theoretical system of traditional Chinese medicine. The medical classics such as Huangdi Neijing, Difficult Classic, Treatise on Febrile Diseases and Shennong Herbal Classic, which came out during this period, marked the establishment of the theoretical system of traditional Chinese medicine, that is, the basic formation of the system of principle, method, prescription and medicine.