Abstract: Aim ：To establish an analytical method to study the chemical components in Zhizi-Gancao-Chi(ZGC) decoction，and investigate its anti-depressant effect. Methods ：An LC-PDA-MS/MS method was established and applied.The separation was performed on an ODS C₁₈ column(250 mm×4.6 mm，5 μm) with a gradient elution.The mobile phase consisted of water/acetic acid(1%，v/v) and methanol.The main components were identified according to the UV and MS.The anti-depressant effect was evaluated with mice tail-suspension test and forced swimming test. Results ：The components of the ZGC decoction were separated isolated and ten of them were identified.These compounds are classified to iridoid glycosides，flavonoids and triterpene saponins.In addition，its anti-depressant effect was observed for the first time. Conclusion ：The LC-PDA-MS/MS method can effectively separate and identify the components of ZGC decoction，which has significant anti-depressant effect.The relationship between the chemical component and its anti-depressant effect needs further study.