This disclosure relates to medicaments and methods for treating and preventing hepatitis B virus-related liver diseases using sufficient dosage. Specifically, the disclosure provides a method for treating and preventing hepatitis B virus-related liver diseases comprising administering to a subject in need of treatment and prevention a sufficient dosage of a polypeptide or a pharmaceutical composition comprising the polypeptide per day, wherein the polypeptide comprises an amino acid sequence derived from hepatitis B virus (HBV) Pre-S1； the sufficient dosage is a daily dosage at which the polypeptide reaches the saturating level in a liver target organ after the polypeptide is administered in the sufficient dose for several days.
