【Abstract】ObjectiveTo investigate whether tumor necrosis factor-α (TNF-α) enhance the expression of vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9(MMP-9) in hepatic cancer cell line HepG2 or not. Methods Cultured HepG2 cells were treated by TNF-α with various concentration and time. The morphological changes of HepG2 cells were studied microscopically and the proliferation of HepG2 were detected by methyl thiazolyl tetrazolium (MTT). The expression of VEGF and MMP-9 mRNA in cultured HepG2 were determined by relative quantitative reverse transcription polymerase chain reaction. The VEGF and MMP-9 protein level in supernatants and in cytoplasm were determined by enzymelinked immunosorbent assay (ELISA) and by immunocytochemical staining, respectively.Results There was a little morphological changes in HepG2 with TNF-α treatment, but no change of cell proliferation in corresponding time. The expression of VEGF and MMP-9 mRNA was enhanced gradually with the TNF-α concentration increasing, the VEGF and MMP-9 protein level in supernatants and in cytoplasm was elevated gradually with the concentration increasing. There was a dependance on the concentration when the concentration of TNF-α was lower than or equal to 104 U/L. Furthermore, the effect of promotion was close to peak when the TNF-α concentration up to 104 U/L; but no timeeffect pattern observed. Conclusion TNF-αJP can enhance the expression of VEGF and MMP-9 at the level of mRNA and protein in hepatic cancer cell line.