Under the influence of the construction of ontology by the Confucians in Song Dynasty and the Confucian scholar experience in the early years

ZHANG Yuansu began to reconstruct the theory of prescription formulation and medication theory to improve his medical theory system. ZHANG took the "qi" and "taste" attributes of medicine as the origin of medicine efficacy

took the thickness and thinness of "qi" and "taste" of medicine as the basis of classification

then introduced the theories of yin and yang

five phases and five evolutive phases and other theories to construct the system; he took "qi" and "taste" medication as the core

and sorted out the "formulation method by qi and taste" and "formulation method by the theory of mutual generation and restriction of five phases method". ZHANG Yuansu took the internal "qi" and "taste" of medicine as the ultimate nature for the elaboration of the external efficacy of medicine. The method of building that theory fully embodies the philosophy of ontology. The prescription formulation and medication theory closely conforms to the theoretical model of "five phases-five Zang-fu viscera-five qi-Yaolei Faxiangzhi theory"

and also enriches the theoretical basis of medicine under the guidance of the theory of "qi transformation of Zang-fu viscera".