The antidepressive effect of Xiaoyaosan is doubtless by researches while the potential antidepressive active ingredients and their mechanisms remain unclear.In order to explain the antidepressive effect of Xiaoyaosan,all of the recent reports were sought out on the current situation of the antidepressive monomer compositions of Xiaoyaosan and their mechanism.By exploring the relationship between the effects and the active ingredients, the mechanism and the active ingredients, the antidepressive active ingredients such as quercetin, isorhamnetin,kaempferol, liquiritin, isoliquiritin, liquiritigenin, isoliquiritigenin, saikosaponinA, saikosaponinD, glycyrrhizinate, paeoniflorin, albiflorin, ferulic acid, curcumin and their mechanism of antidepressive such as regulating the monoamine neurotransmitter systems, regulating the neuroendocrine system, affecting the neural plasticity and neurotrophic, affecting the cellular and molecular mechanisms , affecting the cytokines level, antioxidative stress were summarized.By the overview in the level of monomer rather than formulae, we uncovered the antidepressive mechanism of Xiaoyaosan and further confirmed that Xiaoyaosan, as a classic antidepressive Chinese prescription, had many characteristics, such as multilevel , multichannel, multitarget and so on.