Reactive oxygen species (ROS) are excessively generated in all solid tumors including hepatocellular carcinoma (HCC) creating an oxidative stress microenvironment. In this study, hepatic expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and 8-hydroxydeoxyguanosine (8-OHdG) were investigated in HCC patients. Clinical relevance of these two oxidative stress markers were evaluated. Whether tumor aggressiveness of HCC cells was enhanced by ROS, and if ROS epigenetically up-regulated Nrf2 in HCC cells were investigated. Immunohistochemical staining for Nrf2 and 8-OHdG were performed in hepatic sections obtained from HCC patients. Expression of Nrf2 and 8-OHdG were remarkably increased in HCC tissues compared with the noncancerous hepatic tissues. Elevated expression of 8-OHdG was associated with poor survival in HCC patients. H2O2, an ROS representative, provoked oxidative stress in HepG2 cells, indicated by increased protein carbonyl content and decreased total antioxidant capacity. Nrf2 expression and 8-OHdG formation were markedly increased in the H2O2-treated cells compared with the untreated control. Co-treatment with antioxidants, tocopheryl acetate (TA) and S-adenosylmethionine (SAM), effectively attenuated the Nrf2 and 8-OHdG expression in H2O2-treated cells. HepG2 cells treated with H2O2 had significantly higher migration and invasion capabilities than untreated control cells. These tumor aggressive activities were significantly inhibited by TA and SAM co-treatments. Bisulfite sequencing revealed that CpG dinucleotides in Nrf2 promoter were unmethylated in H2O2-treated cells similar to untreated control. In conclusion, robust histological evidence of increased antioxidative response and oxidative DNA damage in human HCC tissues was demonstrated. Elevated oxidative DNA lesion 8-OHdG was associated with a shorter survival in HCC patients. Experimentally, ROS enhanced NRF2 expression, 8-OHdG formation, and tumor progression in HCC cells. These enhancements were inhibited by antioxidant TA and SAM. The present findings suggest that Nrf2, at least in part, involves in the oxidative stress-induced HCC progression. Antioxidants might be beneficial to decelerate the HCC progression induced by ROS.