Abstract: Objective To identify the status of drug using and the treatment retention during a community-based methadone maintenance treatment(MMT)among heroin users.Methods In-depth interview was conducted to 64 drug users to collect information about factors that related to retention during MMT in Wuxi,Jiangsu.Results 71.8% of the drug users had drug using experience and the main reason was psychological dependence after withdrawal of drug.84.4% of the drug users committed to keep MMT for family and themselves.Conclusion The phenomena of drug using exists in common among patients during MMT.It could be confused directly to the real treatment result.The key point for retention and reducing drug using should put on propaganda and psychological consult.