Hepatocellular　carcinoma　(HCC)　is　one　of　the　most　common　tumor　types　globally.　Despite　the　progress　made　in　surgical　procedures　and　therapeutic　options,　HCC　remains　a　considerable　cause　of　cancer-related　mortality.　In　this　study,　we　investigated　the　antitumor　effects　of　sanguinarine　(Sang)　on　HCC　and　its　potential　mechanisms.　Our　findings　showed　that　Sang　impairs　the　acidic　environment　of　lysosomes　by　inhibiting　cathepsin　D　maturation.　In　addition,　Sang　inhibited　the　formation　of　autolysosomes　in　RFP-GFP-LC3　transfected　cells,　subsequently　suppressing　late　mitophagy.　Sang　also　induced　reactive　oxygen　species　(ROS)-dependent　autophagy　and　apoptosis　in　HCC　cells,　which　was　significantly　attenuated　following　treatment　with　a　ROS　scavenger.　Further　investigation　using　autophagy　inhibitors　revealed　that　sanguinarine-induced　mitochondrial　dysfunction　and　mitophagy　led　to　mitochondrial　apoptosis　in　HCC　cells.　Immunohistochemical　staining　of　sanguinarine-treated　xenograft　samples　revealed　that　it　initiated　and　blocked　autophagy.　In　summary,　our　findings　suggest　that　in　HCC　cells,　Sang　impairs　lysosomal　function　and　induces　ROS-dependent　mitophagy　and　apoptosis.