Abstract: Oral anti-viral agents nucleos (t)ide analogues (NAs) are widely used in treatment of chronic hepatitis B (CHB) since they are well-tolerated in most patients.But clinical relapse occurs in a considerable part of patients after the cessation of NAs therapy.This paper reviews factors related to clinical relapse, including time for drug withdrawal, cccDNA level, age, baseline alanine aminotransferase (ALT) and HBV DNA levels, type of NAs, serum level of HBsAg and the immune status of patients.