Inclusion Criteria:  Patient must be capable of understanding and signing written informed consent; Before commencing the study procedure, participants must obtain informed consent. If the patient is hepatic Coma, the family member shall sign the written informed consent. ≥18 years old. Orthotopic liver transplant for HBV-related disease (such as HCC, DCC or liver failure). Patients were all positive for HBsAg for at least 6 months prior to liver transplantation. HBV DNA ≤ 2000 IU/mL before orthotopic liver transplant . (Including patients who received or did not receive oral antiviral therapy before liver transplantation)  Exclusion Criteria:  Post OLT patients received HBIG Other solid organs transplant recipients HCV, HDV or HIV coinfection Other primary end-stage liver diseases (PBC, PSC, etc) Patients with underwent liver re-transplantation Liver grafts from HBsAg+ donors Graft dysfunction of any other causes HCC with primary portal vein thrombus