Objective To study the mechanism of Bimin Decoctionin on γδ T cells in mice.Methods Rats-derived Bimin Decoction medicated serum was prepared and γδ T cells obtained from mice spleen were isolated and amplified.After activated respectively with Bimin Decoction medicated serum, IL-2 and both Bimin Decoction medicated serum and IL-2,Vδ1 T and Vδ2 T cells were selected negatively.Flow cytometry was used to analyze the effect of Bimin Decoction medicated serum on the signaling pathway of mice γδ T cells.Milliplex method was used to detect the cytokines during activation and proliferation of mouse gamma delta T cells.The expression levels of transcription factors T-bet, GATA3,Foxp3 and RORγ were detected by Western blot method.Results Activation of Bimin Decoction medicated serum with IL-2 could inhibit STAT3 phosphorylation of Vδ1 T cells.The medicated serum decreased IL-4,IL-6 and TNF-α and increased IL-10 secretion significantly.The transcription factor T-bet and GATA3 in the nucleus of γδ T cells were down-regulated and GATA3 was up-regulated when stimulated with medicated serum or IL-2,however there was no significant change in co-activation.Conclusion Bimin Decoction medicated serum could interfere the activation of γδ T cells and the secretion of inflammatory Th1/Th2/Treg/Th17 cells related factors through STAT3 signaling pathway and nuclear transcription factors T-bet and GATA3 in vitro.