Abstract: To observe the relationship between the genotype of HCV, Serum HCV RNA Load, ALT and efficacy of α-interferon on patients with chronic hepatitis C.3MIU of α-interferon was injected intramuscularly every day for 2 weeks at the beginning, then every otherday for 21 weeks in 41 patients with chronic hepatitis C.All patients were tested HCV genotype by INNO-LIPA before therapy.The quantitated and qualitited HCV RNA were measured by PCR before and after therapy every 2 months and 6 months.after treatment.Serum level of ALT and white blood cell were monitored every month after therapy.The rusults showned that 82.8% (24/29) HCV genotype 1b was the end of treatment response (ETR) , 78.9% (15/19) was the sustained response (SR) for HCV RNA.ALT of response was 78.3% (18/23) and 76.5% (13/17) , respectively, in HCV genotype 1b.The rate of sustained response of HC VRNA was higher in lower titier group (≤5×10 5copies/ml) than in high titer group[ (>5×10 5 copies/ml) , P<0.01].The response of ALT not ralated to the ALT level before therapy. (P>0.05) .The study show that serum HCV RNA load before therapy is important to predict the efficacy of α-interferon