OBJECTIVE:To evaluate the effect of Wulong Xiaozheng Wan medicated serum on the epithelial-mesenchymal transition(EMT)of BGC823 cell induced by transforming growth factor-β_1(TGF-β_1)and to explore its mechanism.METHODS:EMT model of BGC823 was stimulated by TGF-β_1.Wulong Xiaozheng Wan medicated serum and LY-364947 were used as intervention.The proliferation and adhesion of BGC823 were detected by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide and flow cytometry was used to detect the apoptosis.The invasion and migration were detected by Transwell.The level of matrix metalloproteins was detected by enzyme-linked immunosorbent assay.The expressions of related proteins and mRNA of EMT marker and TGF-β_1/Smad signal pathway were detected by Western blot and reverse transcription-polymerase chain reaction.RESULTS:Compared with the TGF-β_1 group,Wulong Xiaozheng Wan medicated serum could inhibit the ability of proliferation,heterogeneous adhesion,invasion,and migration.It also promotes apoptosis and homotypic adhesion in BGC823,with a dose-dependent manner.Meanwhile,Wulong Xiaozheng Wan medicated serum could regulate the expression of related proteins and mRNA of TGF-β_1/Smad signaling pathway,and inhibit the expressions of EMT transcription factors and EMT markers.CONCLUSION:Wulong Xiaozheng Wan medicated serum inhibited epithelial-mesenchymal transition by down-regulated the expression of TβRI and the activation of TG F-β_1/Smad signaling pathway.