〔Abstract〕 Objective To investigate the expression level of LONP1 in hepatocellular carcinoma(HCC) and its impact on the occurrence and progression of HCC. Methods The expression of LONP1 in human liver cancer tissues was verified by real-time quantitative PCR(qPCR) and Western blot.LONP1stable knockdown Hep3B and HCCLM3 cell lines were established, and the effects of LONP1 on cell proliferation were explored through CCK-8, EdU incorporation assays, and colony formation assays. The effects of LONP1 on cell migration were assessed using scratch and Transwell migration assays. A Cre-Loxp system was employed to generateLONP1conditional knockout mice, and transcriptomic sequencing of liver tissues was performed to explore the impact ofLONP1deficiency on liver cells. The effects ofLONP1on apoptosis in hepatocellular carcinoma cell lines were explored using Tunel staining and flow cytometry with Annexin V-FITC/PI. Results Western blot and qPCR experiments confirmed the high expression of LONP1 in human liver cancer tissues. Colony formation assays revealed that the number of cell clones inLONP1knockdown groups was significantly reduced compared to the control(P<0.01). CCK-8 and EdU assays demonstrated thatLONP1knockdown cells had a significantly lower proliferation rate than control cells(P<0.01). Scratch and migration assays showed thatLONP1knockdown liver cancer cells exhibited impaired migration compared to controls(P<0.01). Transcriptomic analysis of liver tissues fromLONP1conditional knockout mice indicated that LONP1 might affect apoptosis pathways in liver cells. Tunel staining and Annexin V-FITC/PI flow cytometry showed thatLONP1knockdown increased apoptosis in hepatocellular carcinoma cells. Conclusion LONP1 is highly expressed in liver cancer tissues. The knockdown ofLONP1in liver cancer cell lines promotes cell apoptosis and inhibits cell proliferation and migration.