Sedum sarmentosum Bunge, a Chinese herb, is mainly used for the treatment of chronic viral hepatitis in China, The aim of this work was to examine the cytotoxic activity of S. sarmentosum (aqueous extract, AE) against a human hepatoma cell line (HepG2) in culture.Cell-proliferation ability was determined by the MTT method. Cell-cycle changes and earlier period apoptotic rate of HepG2 cells were detected by flow cytometry. Apoptosis of cultured HepG2 cells induced by AE were observed with a classic laddering pattern on agarose gel electrophoresis. The mRNA levels of Bcl-2 and vascular endothelial growth factor (VEGF) were determined by reverse-transcriptase polymerase chain reaction. The protein expressions of Bcl-2, VEGF, and p-STAT3 were valued by immunocytochemistry.The application of AE to the HepG2 cell culture caused a significant, dose-dependent inhibition of cancer cell growth. It was found that the AE treatment induced apoptosis of the cancer cells, although no changes were found after AE treatment for 48 hours in the HepG2 cell cycle. The mRNA and protein expressions of Bcl-2 and VEGF and the protein level of p-STAT3 were significantly decreased after the AE treatment for 48 hours.This study suggests that AE of S. sarmentosum has potential in preventing and inhibiting effects on hepatocellular carcinoma, which is associated with apoptosis of the cancer cells.