The human hepatocellular carcinoma HepG-2 cells were selected and treated with different concentrations （0， 3.125， 6.250， 12.500， 25.000， 50.000， and 100.000 mg·L^－1） of GA and used as control group and 3.125， 6.250， 12.500， 25.000， 50.000，and 100.000 mg·L^－1 GA groups， respectively. The survival rates of cells in various groups were detected by MTT assay. The HepG2 cells were divided into control group and 6.25， 12.50，and 25.00 mg·L^－1 GA groups. The mitochondrial oxidative phosphorylation（OXPHOS）of Hep-G2 cells was analyzed using energy metabolism analyzer. Flow cytometry was used to detect the mitochondrial membrane potential （MMP） of the cells in various groups. Colorimetry was used to detect the adenosine triphosphate （ATP） levels in the cells in various groups. The expression amounts of cytochrome C （Cyt C） protein in cytoplasm and mitochondria in various groups were detected by Western blotting method. The morphology of cells was measured by acridine orange staining，and Annexin Ⅴ-FITC/PI double staining flow cytometry was used to detect the apoptotic rates of the cells in various groups.

Compared with control group， the survival rates of HepG2 cells in different concentrations of GA groups were significantly decreased（P<0.05）. Compared with control group， the basal respiration， maximum respiration capacities， respiration reserve capacities and ATP levels in 6.25， 12.50， and 25.00 mg·L^－1 GA groups were significantly decreased （P<0.05）；the MMP and ATP levels in the cells were significantly reduced （P<0.05）； the expression amounts of Cyt C protein in the cytoplasm were increased， and the expression amounts of Cyt C protein in mitochondria were decreased； the cells in GA groups were shrank，the nuclei were shattered， and chromatin was aggregated； the early apoptotic rates and late apoptotic rates were increased significantly（P<0.05）.

GA can inhibit the proliferation and induce the apoptosis of Hep-G2 cells，and its mechanism may be related to reducing MMP and inhibiting mitochondria OXPHOS.