Abstract: Objective 　To explore the putative effect of deoxynivalenol on cell cycle and apoptosis of human gastric carcinoma cell line HGC-27 in vitro. Methods 　HGC-27 cells were t reated with DON at different concent rations (50 、100 、1 000 、2 000μg/ L) for 12, 24 and 48 hours, and then cells were harvested for analysis of apoptosis, cell cycle dist ribution and expression of Bax, Bcl-2 and Caspase-3 with flow cytometric ( FCM) and Western Blot methods. Results 　At relatively higher concent rations (1 000 and 2 000g/ L), DON could affect cell cycle dist ribution in a time dependent manner. DON treatment for 12 h, the percentages of cells in G0>>> / G1>>> phases was significantly decreased and that in S phase increased. As the treatment time lasted for 24 h and 48 h, the percentages of cells in G0>>> / G1>>>> phases were significantly increased while that in Sphase decreased ( P < 0. 05 ) . No significant effect s on G2 >>>/ M phase could be found. The apoptosis rates in all DON treated groups for 12 h, 24 h and 48 h were all higher than that in control. Though statistical significance in the difference of apoptosis rate between control and the DON treated groups was not found 12 h after DON treatment but it could be seen 24 and 48 h af ter DON treatment ( P < 0. 05) . Significant dose-effect relationships were found between DON concent rations and the apoptosis rates. Western Blot analysis showed bax and caspase-3 expression was up-regulated and bcl-2 expression was down-regulated in DON treated HGC-27 cells in vitro. Conclusion 　DON could significantly affect the cell cycle distribution of HGC-27 cells in vitro and the effects of DON on cell cycle varied as the concentratrion and treatment time of DON changed. DON treatment could induce apoptosis of HGC-27 cell possibly by up-regulating bax and caspase-3 expression and down-regulating bcl-2 expression.