Objective To study the involvement of mitochondrial pathway in IF203 induced apoptosis in human liver HepG2 cells. Methods HepG2 cells were cultured in DMEM containing 10% fetal bovine serum at 37 ℃ in a humidified atmosphere with 5% COSUB>2/SUB>Inverted phase contrast microscope was used to detect the morphologic changes; Acid phosphatase assay(APA), flow cytometry（FCM）and Western blotting were used to detect the changes of cell viability, apoptosis ratio, mitochondrial transmembrane potential, the expressions of apoptosis-related protein Caspase-9, Caspase-3 and cytochrome C. Results Cell growth was inhibited after HepG2 cells were co-cultured with different concentration of IF203 for 24 hours and 48 hours. HepG2 cells showed round and shrank after they were co-cultured with IF203 of 10 mg/L. Apoptosis ratios caused by IF203 were increased. Mean fluorescence intensity (MFI) of mitochondrial transmembrane potentials in HepG2 cells decreased. The expressions of apoptosis-related protein Caspase-9 and Caspase-3 decreased, but the cytochrome C expression increased. Conclusion IF203 could significantly restrain cell growth of liver cancer cell line HepG2- IF203 can activate mitochondrial signaling pathway which would induce apoptosis, b