Drug use among adolescents is becoming a serious social problem in Taiwan. Along with influences from the mainstream culture, aboriginal adolescents also confront ethnic identity conflicts and social maladjustment, which together may lead to drug use. The purpose of this study is to propose and test a structural model of drug use behaviors among aboriginal adolescents in Taiwan. Research participants were 1091 aboriginal junior high school students in Eastern Taiwan. Structural equation modeling was used in the analysis. The dependent variables are drug use behaviors. Ethnic identity, personality characteristics (self-esteem, locus of control), social learning (peer, family), and beliefs about drug use were used to predict drug use behaviors. The hypotheses and proposed paths of the model are supported. Ethnic identity did not have significant direct effect on drug use behaviors, but have a significant indirect effect through the mediator of personality characteristics. Social learning has the strongest direct effect as well as a significant indirect effect through the mediator of beliefs about drug use on drug use behaviors. Based on the findings, the prevention strategies for drug use among aboriginal adolescents are suggested for relevant service agencies, parents, teachers and counselors.