BACKGROUND:　Personalized　neoantigen　vaccine　could　induce　a　robust　antitumor　immune　response　in　multiple　cancers,　whose　efficacy　could　be　further　enhanced　by　combining　with　programmed　cell　death　1　blockade　(α-PD-1).　However,　the　corresponding　immune　response　and　synergistic　mechanisms　remain　largely　unclear.　Here,　we　aimed　to　develop　clinically　available　combinational　therapeutic　strategy　and　further　explore　its　potential　antitumor　mechanisms　in　hepatocellular　carcinoma　(HCC).　METHODS:　Neoantigen　peptide　vaccine　(NeoVAC)　for　murine　HCC　cell　line　Hepa1-6　was　developed　and　optimized　by　neoantigen　screening　and　adjuvant　optimization.　Then　the　synergistic　efficacy　and　related　molecular　mechanisms　of　NeoVAC　combined　with　α-PD-1　in　HCC　were　evaluated　by　orthotopic　HCC　mouse　model,　single-cell　RNA　sequencing,　tetramer　flow　cytometry,　immunofluorescence,　etc.　The　tumor-killing　capacity　of　CD8+　tissue-resident　memory　T　cells　(CD8+　TRMs)　was　assessed　by　orthotopic　HCC　mouse　model,　and　autologous　patient-derived　cells.　RESULTS:　NeoVAC,　which　consisted　of　seven　high　immunogenic　neoantigen　peptides　and　clinical-grade　Poly(I:C),　could　generate　a　strong　antitumor　immune　response　in　HCC　mouse　models.　Significantly,　its　efficacy　could　be　further　improved　by　combining　with　α-PD-1,　with　80%　of　durable　tumor　regression　and　long-term　immune　memory　in　orthotopic　HCC　models.　Moreover,　in-depth　analysis　of　the　tumor　immune　microenvironment　showed　that　the　percentage　of　CD8+　TRMs　was　remarkedly　increased　in　NeoVAC　plus　α-PD-1　treatment　group,　and　positively　associated　with　the　antitumor　efficacy.　In　vitro　and　in　vivo　T-cell　cytotoxicity　assay　further　confirmed　the　strong　tumor-killing　capacity　of　CD8+　TRMs　sorting　from　orthotopic　mouse　HCC　or　patient＇s　HCC　tissue.　CONCLUSIONS:　This　study　showed　that　NeoVAC　plus　α-PD-1　could　induce　a　strong　antitumor　response　and　long-term　tumor-specific　immune　memory　in　HCC　by　increasing　CD8+　TRMs　infiltration,　which　might　serve　as　a　potential　immune-therapeutic　target　for　HCC.　©　Author(s)　(or　their　employer(s))　2022.　Re-use　permitted　under　CC　BY-NC.　No　commercial　re-use.　See　rights　and　permissions.　Published　by　BMJ.