Depression is a kind of complex mental illness， which is mainly treated by western medicine at present， but the effect of western antidepressant drugs is not good due to the combined influence of side effects and individual differences of patients. Depression is a "stagnation syndrome" in traditional Chinese medicine， and its treatment principle is to disperse stagnated liver Qi for relieving Qi stagnation. The classic traditional Chinese medicine formula Chaihu Shugansan （CHSGS） has a long history of treating depression and demonstrates significant therapeutic efficacy. Clinically， the addition and subtraction of CHSGS is flexible， but the properties of the active ingredients are vague， and the mechanism and function are unclear. In order to elucidate the pharmacodynamic basis and antidepressant mechanism of CHSGS， this article reviews the pharmacodynamic material basis of CHSGS， clinical research and antidepressant mechanism research progress. Clinically， CHSGS can treat various types of depression such as primary depression， post-stroke depression， and postpartum depression. This article summarizes 32 main ingredients of CHSGS， among which albiflorin， ferulic acid， naringin， hesperidin， saikosaponin a， glycyrrhetinic acid， tangeretin， meranzin hydrate， nobiletin and glycyrrhizic acid are the quality markers （Q-markers） for the antidepressant effect of CHSGS. The antidepressant mechanism of CHSGS is complex， including regulating monoamine neurotransmitters， hypothalamic-pituitary-adrenal （HPA） axis， neurotrophic factors， inflammatory response， cell damage-related pathways， oxidative stress， etc. This article helps to deeply understand the pharmacodynamic basis and mechanism of CHSGS in treating depression， and provides a theoretical basis for the clinical application of CHSGS in treating depression and the development of antidepressant drugs.