Objective: To detect the activities of anti-hepatitis B iRNA with cellular immunol. and humoral immunol. methods.Methods: 2mg/mL anti-hepatitis B iRNA was injected into rats once another day for three times as the exptl. group, at the same time saline was injected to the control group.Then the cellular immunity was detected by phagocytosis of macrophages and leukocyte adherent inhibition (LAI), and the humoral immunity was detected by enzyme-linked immunoadsorbent assay (ELISA) and indirect hemagglutination.Results: In the exptl. group, the phagocytosis rate of macrophages significantly increased, however the adherent rate of LAI markedly decreased, and HBsAb in the serum was detected, compared with those in the control.These methods could be used to determine the activity of anti-hepatitis B iRNA.