Abstract: ObjectiveTo evaluate the effectiveness of methadone maintenance treatment(MMT)for heroin addicts in Changzhou city,Jiangsu province.MethodsTotally 371 heroin addicts who had stayed in Changzhou methadone maintenance treatment clinic for more than one year were surveyed with a questionnaire and detected for HIV and HCV.ResultsThe most of the subjects were middle-aged married male.The mean age at first drug use was 26.7 years old.The average length of drug abuse was 8.2 years.After MMT,the proportion of injecting drug use in the previous one month dropped from 73.0% to 16.7%.The proportion of heroin addicts with more than two sexual partners dropped from 6.0% to 0.5%.The proportion of condom use in the last sex raised from 14.3% to 28.1%.The proportion of contact with drug use friends more than one time per day in the previous one month dropped from 19.7% to 7.3%.However,there was no significant improvement in the proportion of crime commitment,the relationship with family members,and the status of employment.ConclusionMethadone maintenance treatment can change injecting drug behavior and reduce times of contact with the former drug abuse friends,and improve safe sex.Patients should be given more individual couseling and social help to increase the effects of MMT.