In recent years, adolescent drug use is becoming more and more serious. The drug use behavior of reform school students is worse than the drug use behavior of middle school students (Lin, Su, Hu, & He, 2010; Xie, Bu, Liang, Mai, & Zhao, 2007). The younger adolescent beginning to use drug is, the bigger possibility of using drug in whole life is (Lin, Fan, Fang, Tan, & Li, 2010). Drug use greatly endangers adolescents health and may make them death. They can lead to serious adolescents behavioral problems, such as adolescents crime and suicide (Estévez & Emler, 2011; Ma, Guo, & Pan, 2010; Tang et al., 2009). Therefore, more attention should be paid to drug use among reform school students. It is very necessary to study the potential mechanisms of drug use of reform school students so as to design prevention and intervention programs. The present study aimed to explore characteristics of drug use of reform school students and to explore the mediated moderation among sensation seeking, stressful life events, affiliation with deviant peers, and drug use after controlling for several demographic variables. A sample of 523 reform school students of 9 reform schools (442 boys and 81 girls, Mage=14.13±0.84) was recruited in the study to complete self-report questionnaires. The self-report questionnaires used in this study included sensation seeking scale, stressful life events scale, affiliation with deviant peers questionnaire, and drug use questionnaire． The results indicated that: (1) reform school students had a high level of drug use. About 32% of the reform school students used drugs, characterized by using drugs in a younger age, mainly using new drugs; (2) reform school students’ sensation seeking was a risk factor of drug use, which confirms the results from earlier studies that have found a positive relationship between sensation seeking and adolescents drug use; (3) stressful life events moderated the effect of sensation seeking on drug use; (4) affiliation with deviant peers mediated this moderation effect. The theoretical and practical implications of the results was further discussed. Future direction in the field of the relationship between sensation seeking and adolescent substance use was prospected.