To investigate the killing effect ofphotodynamictheraphy(P DT)mediated by photosensitizerBF01on human hepatocellular carcinoma cell line bel-7402in v it ro and the tumor suppressor effect in vivo and its action mechanism.CCK-8methodw as employed to determine the same laser intensity and different drug concentrations(0、0.8、1.6、3.2、6.4μmol·L－1；laser doses 2.4J/cm²,illumination t ime:1min/well,laser wavelength of 652nm) BF01-PDT on the proliferation of bel-7402and IC50,Cell apoptosis and necrosis we re measured by DAPI staining and flow cytometry with AnnexinV-FITC /PI double staining,RO S of bel-7402human hepatocellular carcinoma cells was detected．Confocal microscopy a ssaywas used to observe BF01subcellular localization on bel-7402cells．A bel-7402-bearin g NU /NU mice model wasestablished,and the tumor volume was measured todraw the growth curve.The t umor growth curve was plotted and the therapeutic effect was observed.CCK8assay sh owed that BF01-PDT could significantly inhibit bel-7402cell.When the concentration o f BF01was 6.4μmol·L－1,the killing rate was 86%,and half of the killin g concentration IC50was 2.46μmol－1.BF01subcellular localizationwas tightly cellular correlated,it mainly localized in mitochondria in bel-7402．The detection of cell death was mainly based on la t e apoptosis,DAPI staining and flow cytometric analysis showed that BF01-PDT could induce apoptos is of bel-7402. ROS levels of bel-7402human hepatocellular carcinoma cells were increased afte r BF01-PDT．The in vivo experiments demonstratedthat BF01-PDT significantly inhibited the growt hof bel-7402tumor．BF01-mediated PDT has a significant lethal effect on bel-7402cells invitro and in vivo．The lethal effect of PDT on cancercells is shown in the apoptosis a nd can be attributed to BF01subcellular localization in mitochondria in bel-7402,and th e increased ROS levels of bel-7402human hepatocellular carcinomacells．