Traditional Chinese medicine(TCM)is an important part of the traditional culture of the Chinese nation.It has very important theoretical and practical significance to maintain and carry forward the characteristics of Chinese medicine.The development of Chinese Materia Medica has undergone supplementation and improvement by different pharmacists in different periods，and it contains very practical clinical value.Among them，the properties of traditional Chinese medicine with property and taste and meridian as the main part are the core of TCM theory and have been highly praised by doctors of the past dynasties.On the basis of inheriting the predecessor's pharmacy theories，the Yishui School of Kaishan ZHANG Yuansu，combined with its own clinical medicine experience，completes the theoretical system of Chinese medicine and has a far-reaching influence.This paper attempts to systematically analyze ZHANG Yuansu's theory system of Chinese medicine in Medical Origin and the characteristics of the rule of medication in terms of breadth and depth.Specifically，it mainly starts from 7 aspects of drug，the nature of the ascending and descending of the drug，the theory of quotation and report，the seasonal medication，the compatibility of the drug，the replenishment and reduction of the drug，and the medication for disease differentiation，so as to clarify the application of the element of ZHANG Yuansu，law theory and application characteristica and provide references for TCM practitioners.