Objective:To explore the anti-tumor mechanism of paeoniflorin by human gastric cancer cell line SGC7901/VCR. Methods:After SGC7901/VCR cells were treated with paeoniflorin in different concentration for 48 h,methyl thaizolyl tetrazolium(MTT) method was used to detect the inhibition rates of the cells. Flow cytometry(FCM) was employed to detect SGC7901/VCR cell apoptosis ratios.Western blot was used to test the expression of NF-κB,Bcl-2 and Bax. Activation of NF-κB transcription was detected by ELISA. Results:Paeoniflorin restrained cell proliferation and induced apoptosis of SGC7901/VCR cells in a dose-dependent manner. Paeoniflorin significantly inhibited the activity of NF-κB in nuclear. The inhibition pattern of NF-κB was confirmed by western blot and ELISA. After SGC7901/VCR were treated with 0,40,80,160,320 μg/ml of paeoniflorin for 48 h respectively,the protein levels of Bcl-2 were down-regulated in a dose-dependent manner,while those of Bax were not affected. Conclusion:Paeoniflorin can inhibit the proliferation and induce the apoptosis of SGC7901/VCR cells,which might be partly related to Bcl-2 up-regulation by inhibiting NF-κB activation.