Zhang Yuansu, styled Jiegu, was born in Yizhou (now Yi River County, Hebei) in the Jin Dynasty. Being a knowledgeable man of great attainments in several fields, he had rich clinical experience and was good at adapting methods of the past to the present use. He established the organ-centered clinical treatment system and innovative medication theory, starting a new stage in the medicine of Jin and Yuan Dynasty, which had a significant impact on later medicine. Channel entry (gui jing) is one of the properties attributed to Chinese medicinals. Channel entry theory is the product of exploration and development by generations practicing physicians in China and that reflects the effects of Chinese medicinals on the human body. Clinically, channel entry theory further completes the body of theory concerning medicinal properties, yet its greatest significance is that it enhances the accuracy of clinical application. Channel conduction (yin jing) is based on the theory of channel entry, the main difference between the two being that the theory of channel entry applies to single medicinals, while channel conduction applies to combinations. Zhang completed the logic of the theory of channel entry and the medicinal conduction. This paper aims to discuss the features of these two theories.