Objective To explore the dynamic changes and the factors influencing changes of peripheral blood cells in patients with chronic hepatitis C receiving interferon alpha 2b with ribavirin therapy, and to clarify the impact of peripheral blood cells changes on SVR rates.Methods 343 CHC patients were enrolled.All patients received IFN-alpha-2b combined with ribavirin for 48 weeks.The peripheral blood cells and serum HCV RNA level were assessed at baseline and every 12 weeks during treatment, as well as in the follow-up after cessation of therapy.