The implementation of the MMT program in China is one of the most significant measures ever taken by the Chinese government to address drug use and HIV prevention challenges. In 2004, China launched a series of MMT programs at eight pilot clinics in five provinces. By December 2007, 503 MMT clinics had been established nationwide across 23 provinces. Several studies have found that positive outcomes in drug use, criminality, and employment were associated with participation in MMT. However, special challenges are facing the current MMT programs are facing: 1) clients' drop-out rates are high; and 2) providers at MMT clinics do not have sufficient training, and some of them hesitate to serve the population. We have recognized the urgent need and conducted the study to address these challenges.