Aim To investigate the effects of tetrahydroxystilbene-2-O-β-D-glucoside(TSG) on the apoptosis of human umbilical vein endothelial cells(HUVEC) and its molecular mechanisms induced by hydrogen peroxide(H2O2).Methods The model of apoptosis HUVEC was induced by 300 μmol/L H2O2,MTT assay was used to detect the cell proliferation,flowing cytometry was used to measure the effect of apoptosis.The expression of Bcl-2 and Bax was detected by Western blot.Results H2O2 could inhibit the viability of cells,decrease the expression of Bcl-2 and the ratio of Bcl-2/Bax,and increase the apoptosis ratio and the expression of Bax.On the contrary,treatment of TSG could improve the rate of cell proliferation,inhibit cell apoptosis,up-regulate the expression of Bcl-2 and increase the ratio of Bcl-2/Bax,down-regulate the expression of Bax significantly(P<0.01).Conclusions TSG could inhibit H2O2-induced apoptosis of HUVEC,and the mechanisms might be associated with regulating the expression of Bcl-2,Bax and the ratio of Bcl-2/Bax.