Abstract: Objective To study the change of IFN-γ secreted by peripheral blood mononuclear cells（PBMC） and interleukin-17（IL-17） in chronic hepatitis-B patients during ETV therapy. Methods PBMC isolated from venous blood taken from HBV-infected patients at different time points of ETV therapy,were cultured with anti-CD3,anti-CD28 and HBcAg to stimulate secretion of IFN-γ and IL-17 by PBMC.Serum HBV-M,ALT,HBV-DNA,and ALT levels were measured. Results The ALT,HBV-DNA,and IFN-γ levels in chronic hepatitis-B patients were significantly lower 4 weeks after ETV therapy.The serum IL-17 level in supernatant was significantly higher 4 weeks after ETV therapy and then gradually decreased. Conclusion Early ETV therapy can suppress HBV replication by reducing immune tolerance and increasing IL-17 secretion.With the further suppression of HBV,the IL-17 and IFN-γ level is decreased,thus improving inflammation reactions in the liver.However,it may impair the ability of body to clear HBV.