AIM To study the long-term efficiency of therapy with Interferon alpha (IFN-a) in patients with HCVRNA positive chronic hepatitis C.METHODS Ten patients were enrolled in the study, whose age 31 -62 years (mean 53 years), course 6- 72months (mean 24 months), of whom, 6 patients with mild CHC, 4 moderate CHC. All patients receivedIFN-a 3 MU three times weekly for six to twelve months, and then followed up for seven years after the endof treatment. The results of hepatic functions and HCV RNA at the end of treatment and follow-up period inall patients were observed.RESULTS ( At the end of treatment, clinical symptoms recovered obviously in all patients, virologicalresponse (defined as HCV RNA loss) occurred in 5 of 7 (71.4%) patients (60 years old). At the end of follow-up, the rates of HCV RNA loss were 42.9% (3/7)and 33.3% (1/3), respectively, in these group. Virological sustained response (defined as HCV RNA loss atthe end of treatment and follow-up) occurred in 3 of 6 (50%) patients (6 - 12 month-course) and in 1 of 4(25%) patients (> 12 month-course). A sustained HCV RNA response was observed in 2 of 7 (28.6%)patients with IFN-a therapy for 6m and in 2 of 3 (66.7%) patients with IFN-a therapy for more than 6 m. Ofall patients, 4 patients with sustained HCV RNA response were mild CHC, 4 patients with sustained HCVRNA positive were mild CHC (2 patients), moderate CHC (2 patients), respectively; other 2 patients withHCV RNA loss at the end of treatment but recurred at the end of follow-up, were moderate CHC. ②Biochemically sustained response (defined as ALT normalization at the end of treatment and follow-up) wasobserved in 5 out of 10 (50%) patients, and these 5 patients were mild CHC, of whom, 4 patients with HCVRNA sustained negative, 1 patient with HCV RNA loss and then recurred again. Two patients with ALTnormalization at the end of follow-up were one mild CHC, one moderate CHC, respectively. Other 3patients with no response were moderate CHC, of whom, 2 patients with HCV RNA sustained positive, 1patient with HCV RNA loss then recurred, and in these 3 patients, the lower limits of ALT were more than121 U/L- 148 U/L. ③ Of 10 patients, 3 moderate CHC patients were far from satisfactory to IFN-αtherapy, of whom, 2 coinfected with HBV, t with post-hepatitis cirrhosis.CONCLUSION The CHC patients with younger age, shorted course, and lighter liver changes in biopsy(mild CHC) have better response to IFN-α therapy, and the efficiency of therapy with IFN-α for 12 m aremore satisfactory than those for 6 m. The patients with coinfected HCV and HBV have a response to IFN-αtherapy worse than the others.