Abstract: Objective To explore the relationship between SEPT9 gene and hepatocellular carcinoma,and to reveal the role of SEPT9 in tumorigenesis and development of hepatoma. Methods The expression vector containing SEPT9 gene was transfected into the human hepatoma cell line HepG2 with LipofectamineTM2000.The transfection efficacy was studied under fluorescence microscopy,and the mRNA and protein levels of SEPT9 were detected with reverse transcript polymerase chain reaction (RT-PCR) and Western blot assay.CCK-8 method was used to detect cell proliferation,and FCM was served to detect the cell apoptosis. Results The transfection efficiency was up to 70%,and expression of mRNA and protein of SEPT9 were suppressed significantly.And the result of CCK-8 assay showed significantly inhibition of in the experiment group,and FCM assay showed that the apoptotic rate in the experiment group increased significantly comparing to the control group (P<0.05 ). Conclusion Suppression of the expression of SEPT9 gene can effectively inhibit the proliferation of HepG2 cell,and promote apoptosis significantly.