Abstract: Objective To explore the mitochondrial pathway in the apoptosis of Hela cells induced by TRAIL. Methods Apoptotic cells were detected by DNA electrophoresis. The mitochondrial transmembrane potential (∆Ψm), the expressions of Bcl-2, the location of Cyt c and AIF, the caspase-3 activity were tested by confocal laser microscopy, western blot, immunofluorescence and caspase-3 activity assay. Results TRAIL can induce apoptosis in Hela cells. DNA ladders were showed on agarose gel electrophoresis. At the same time, TRAIL induced the decrease of ∆Ψm and Bcl-2, the release of Cyt c, the translocation of mitochondrial AIF to cytoplasm and nuclei, the increase of caspase-3 activity in the time-dependent manner. Conclusion TRAIL induce the apoptosis of Hela cells involves mitochondrial signal pathway.