Abstract: To study the anti-tumor activities and the related mechanisms of dicumarol, the CCK-8 method was used to identify anti-tumor activities of dicumarol. HepG2 cells were used to explore the anti-tumor mechanisms by measuring several physiological and biochemical indexes. The results show that dicumarol can significantly inhibit the growth of HepG2, Hccc-9810 and MDA-MB-231 cell lines in a dose-dependent and time-dependent manner, with HepG2 cells showing the greatest sensitivity to dicumarol (with an IC₅₀ value of 3.19±0.68 µmol·L^-1 at 48 h). Dicumarol arrested the cell cycle at S phase and down-regulated the expression of anti-apoptotic protein Bcl-2 while promoting the expression of the pro-apoptotic proteins Bax and cleaved caspase-9. Dicumarol significantly decreased the levels of glutathione (GSH) and superoxide dismutase (SOD) in HepG2 cells, and increased the levels of malonaldehyde (MDA) and reactive oxygen species (ROS). Dicumarol also down-regulated the protein levels of NAD(P)H quinone oxidoreductase 1, 3-phosphoinositide-dependent protein kinase 1, and hypoxia inducible factor-1α under hypoxic conditions. The above results show that dicumarol can inhibit the proliferation of HepG2 cells and induce cycle arrest and apoptosis. Dicumarol may down-regulate the expression of HIF-1α by inhibiting the activity of NQO1 and PDK1, which leads to the accumulation of ROS, thereby generating oxidative stress and inducing apoptosis in HepG2 cells.