Abstract: There is a dose-effect relationship in Chinese drug prescriptions. With different combination of drugs in the prescription, the dosage of each drug varies, and the drugs in combination supplement or counteract each other. One of the differences between Chinese drugs and chemical drugs is the fact that Chinese medicine pays attention to the syndromes, which is also the basis for the dose-effect relationship in Chinese drug prescriptions. The effect of Chinese drug prescriptions is the manifestation of the interaction between components and the human body. The authors put forward the view that there exists dose-effect relationship in classical prescriptions, i.e. the two-phase two-period characteristics (the former referring to effect on syndromes and effect on diseases; the latter referring to the two period of time of effectiveness corresponding to the two phases), and the five-element (disease, structure, dosage, substance, efficacy) correlation regularity.