We reported a case of Hepatitis B virus-related membranous nephropathy (HBV-MN) with improvement under an ongoing 4.5-year of entecavir monotherapy. A 37years old man with a 5years’ history of chronic hepatitis B (CHB) who was taken to our department because of proteinuria and microscopic haematuria. A renal biopsy led to a diagnosis of HBV-MN with mesangioproliferative. Interferon-alpha 2b (IFN-⍺2b) was stopped after 24weeks due to the increasement of HBV-DNA and sustained HBeAg positive. Therefore, we started using 0.5mg entecavir per day. After 2months’ treatment, HBV-DNA was not detected in the blood, and the ALT and AST decreased to normal degree. After 3years of entecavir therapy, virological tests revealed HBeAg seroconversion. With no further intervention during the next one and a half years, there was improvement of proteinuria gradually. This suggested that entecavir monotherapy may induce and maintain complete remission of membranous nephropathy associated with hepatitis B.