Abstract： Objective:To investigate the clinical efficacy and safety of transarterial chemoembolization (TACE) combined with lenvatinib plus PD-1 inhibitor (TACE+Len+PD-1) versus TACE combined with lenvatinib (TACE+Len) for patients with unresectable intermediate-advanced hepatocellular carcinoma (HCC).Methods:The data of 94 patients with intermediate-advanced HCC who received TACE+Len+PD-1 (One week after TACE, the patient were treated with lenvatinib and PD-1 inhibitor. lenvatinib, 8 or 12 mg/d, orally; PD-1 inhibitor, 200 mg/3 weeks, iv) or TACE+Len (One week after TACE, the patient were treated with lenvatinib.lenvatinib, 8 or 12 mg/d, orally) in the Second Affiliated Hospital of Guangzhou Medical University from June 2019 to February 2021 were collected and retrospectively analyzed. Among these patients, 44 were in the TACE+Len+PD-1 group and 50 were in the TACE+Len group. Tumor responses were evaluated according to modified response evaluation criteria in solid tumors. Objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), overall survival (OS) and adverse events (AEs) were compared between the two groups. The potential prognostic factors for PFS and OS were determined.Results:The ORR of TACE+Len+PD-1 group and TACE+Len group was 72.8% (32/44) and 52.0% (26/50) (χ2=4.25, P=0.039), respectively. The DCR of TACE+Len+PD-1 group and TACE+Len group was 86.4% (38/44) and 62.0% (31/50) (χ2=7.12, P=0.008), respectively. The median PFS and median OS in TACE+Len+PD-1 group were significantly longer than those in TACE+Len group (PFS, 7.9 vs. 5.6 months, χ2=7.91, P=0.005; OS, 18.5 vs. 13.6 months, χ2=4.40, P=0.036). Multivariate Cox regression analyses showed that TACE+Len (HR=2.184,95%CI 1.366-3.493), incomplete tumor capsule (HR=2.002,95%CI 1.294-3.209) and extrahepatic metastasis (HR=1.765,95%CI 1.095-2.844) were the independent risk factors for PFS, while TACE+Len (HR=2.081,95%CI 1.097-3.948) and BCLC stage C (HR=7.325,95%CI 2.260-23.746) were the independent risk factors for OS. The incidence of ≥grade 3 AEs in TACE+Len+PD-1 group was similar to that in TACE+Len group (χ2=0.45, P=0.501). Conclusion:Compared with TACE+Len, TACE+Len+PD-1 resulted in a better tumor response and a longer PFS and OS in patients with intermediate-advanced HCC.