It has not been long since beginning of the research of dose-effect relationship of TCM， therefore the methods and theories have not been established yet.When the disease， syndrome， prescription and herbs are determined， it is the dose of the prescription that decides the efficacy， and that there is the optimal dose range.Dose-effect relationship can be expressed by dose threshold， including Median effective dose， or Medium dose（［D］0.5）， Optimal dose range（［D］0.8~［D］0.2）， Threshold dose（［D］0.2）.Even if the disease， syndrome， prescription and herbs are determined， the effect of TCM compound formula remains a complicate issue.There are the global effect， the organism effect， the molecular effect， accordingly there should be corresponding threshold dose ranges.