Abstract: Objective To describe the characteristics and related factors of cigarette smoking behavior among methadone maintenance treatment(MMT)outpatients.Methods A total of 564 MMT outpatients were screened for smoking behavior and subdivided into smoking group and non-smoking group,with 102 frequency matched(gender,age±3 years and education level)smokers selected from communities.All participants completed the social-demographic questionnaire,Fagerström Test for Nicotine Dependence(FTND),and Russell's Reasons for Smoking Questionnaire.Logistic regression was used to identify associated factors.Results The detection rate(95% confidence interval)of cigarette smoking behavior was 92.9% (90.8%-95.0%).The FTND scores for smoking group and community smoker group were 5.99±2.41 and 4.40±2.50,respectively.The smoking group had a higher FTND score than community smokers group(P<0.001).Smoking was associated with self-employed people/temporary worker(odds ratioOR=20.8),jobless/unemployment(OR=16.2),remarriage(OR=2.31),and long MMT period(OR=1.18).Conclusion MMT outpatients are prone to be tobacco dependent and their smoking behavior is of addiction and dependence characteristics and relates to sociodemographic factors and MMT.