Abstract: Objective To describe the characteristics of HCV infection among drug users of Wuxi,Jiangsu,and provide baseline data for valid intervention.Methods Face-to-face interview using detailed questionnaire was conducted amongst 794 drug users in the methadone maintenance therapy(MMT)clinic of Wuxi,and blood sample was collected and tested for HCV antibody.Results The overall anti-HCV antibody-positive rate was 85.6%,while the rate was 92.5% among 683 IDUs,significantly higher than that of NIDUs(21.4%,χ²=265.40,P<0.001),and also higher than those users of intramuscularly/intradermal addicts(42.9%),syringe addicts(20.0%)and oral addicts(18.2%)(χ²= for trend=256.16,P= 0.000).Of 617 users,528 individuals(85.6%)who shared syringes had a higher HCV infection rate(95.5%)compared to those who do not(24.7%),while HCV infection rate was 95.8% among direct syringe sharers(307,58.1%)and 95.3% among indirect ones(510,96.6%).Average durations of drug use and intravenous drug use were 9.84±2.87 and 4.96± 3.12 years,respectively.A significantly higher HCV infection rate was found among drug users who have more than 5 sex partners,compared to those who have single sex partner.Conclusion High HCV infection rate was observed among drug users in MMT clinic of Wuxi,and behaviors athigh risk were commonly identified.HCV serological and behavior monitoring shoud be applied in the MMT programs,and strategies and measures for comprehensive intervention should be implemented to reduce HCV infection rate and control the transmission from the source population to the general population.