Objective:To investigate the changes of immunoglobubin and complement in peripheral blood after administering entecavir in patients with chronic hepatitis B. Methods:The changes of immunoglobulins in peripheral blood of ninety-five patients with chronic hepatitis B before and after treatment with entecavir were detected by flow cytometry. Serum complement C3 and C4 were measured by Beckman-Coulter Immage 800 immunochemical system and its kit. HBs Ag was detected by Abbott chemiluminescence method. At the same time

80 cases of healthy controls were enrolled. Results:After six months of entecavir treatment

the liver function of ninetyfive patients had significantly improved and the level of HBs Ag titer reduced significantly（P<0.05）. Among them

level of HBs Ag titer of twenty-six cases（27.3%）decreased >500 IU/m L. The levels of Ig G

Ig M and Ig A were significantly increased after treatment with entecavir

and the loads of serum complement C3 and C4 before and after the therapy of entecavir was（0.602±0.112）g/L and（0.113±0.075）g/L

（1.201±0.156）g/L and（0.196±0.033）g/L

respectively（P<0.05）. Conclusion:The degrees of cellular immune function can be low in the patients with chronic hepatitis B

but it will be correlated with the efficacy of entecavir.