To investigate the effect and mechanism of exopolysaccharides from Fusarium graminearum (FGEPS) on human gastric cancer SGC-7901 cells.Fusarium graminearum was fermented in liquid medium.The exopolysaccharides were separated by alcohol precipitation,decolorization,deproteinization and dialysis,and analyzed by high performance gel permeation chromatography (HPGPC),infrared (IR) and ultraviolet (UV) spectroscopy.CCK-8 method was used to detect the proliferation inhibition activity of SGC-7901,BGC-823,and MGC-803 cells.Effects of FGEPS on apoptosis of SGC-7901 cells were analyzed by Annexin V-FITC/PI,JC-1 and Hoechst 33258 staining.The expressions of pro-apoptotic proteins Bax,Cleaved Caspase-3,Cleaved Caspase-9 and anti-apoptotic protein Bcl-2 were detected by Western blot.FGEPS was isolated from the fermentation broth of Fusarium graminearum,which had the characteristic absorption of polysaccharides and contained four components. In vitro anti-tumor activity assay showed that FGEPS inhibited SGC-7901 cells more significantly than BGC-823 and MGC-803 cells.FGEPS could significantly reduce the mitochondrial membrane potential of SGC-7901 cells,induce the concentration of nuclear chromatin,and produce apoptotic bodies (P<0.05 or P<0.01).FGEPS could raise the expression of pro-apoptotic proteins Bax,Cleaved Caspase-3 and Cleaved Caspase-9 in SGC-7901 cells (P<0.01 or P<0.001),and reduce the expression of anti-apoptotic protein Bcl-2 (P<0.001).In summary,FGEPS isolated from the fermentation broth of Fusarium graminearum could induce apoptosis of SGC-7901 cells through mitochondrial pathway.