263 patients with chronic hepatitis C who received interferon therapy were followed up for an average 2.7 years after therapy. 36% of patients showed complete response, 16% of patients showed partial response, 48% of patients showed no response. 96 patients underwent liver biopsy after therapy and were observed long-term prognosis. 13 cases developed to liver cirrhosis. Histopathology before and after interferon, HCV-DNA probe before therapy were examined.