The investigators propose to conduct 3 inter-related studies over 4 years using both qualitative and quantitative research methods to address a series of research questions. Firstly, The investigators will begin by assessing HCV/HIV knowledge, attitudes, perceptions, risk behaviors, and infection among IDUs in MMT clinics (Study 1) and HCV/HIV knowledge, attitudes, and HCV/HIV-related services among MMT staff (Study 2). Secondly, based on knowledge accumulated from Studies 1 \& 2; The investigators will adapt and develop HCV/HIV education materials appropriate for Chinese IDUs and drug treatment service providers, and then use the Transtheoretical Model of Behavior Change as a conceptual model to measure if our educational program will increase patients' readiness to consider changing HCV/HIV risk behaviors and getting medical care for HCV/HIV (Study 3). Finally, by integrating findings of these three studies and by consulting with leading experts in HCV/HIV. The investigators plan to develop HCV/HIV intervention program applicable in China, which can be tested in future formal experimental trials.
