A large body of research has documented the positive association between school climate and adolescents’ problem behaviors. However, the measurement and analysis of school climate remains to be improved. Many studies have aggregated students’ personal experiences items (e.g., “our teachers care about me”) with items referring to school characteristics (e.g., “In this school, teachers help students solve problems”). This confusion makes it hard to disentangle the effects of students’ experiences from the effects of schools’ characteristics or climate. To solve this problem, we deleted the items which referring to the students’ personal experiences. Besides, some single-level analyses erroneously conflate individual- and school-level effects, this approach make it hard to disentangle the effects of students’ experiences from the effects of schools’ climate. In order to disentangle them, we used the method of group-mean-centered technology as suggested by Morin et al. (2013). In addition, little is known about the mediating mechanisms underlying this relation. The present study examined the mediating role of peer victimization between school climate and problem behaviors (i.e., depression, delinquency). A total of 2,758 junior high school students (mean age = 13.56 years) from 10 schools of Guangdong province were invited to take part in this study. Participants anonymously completed Socioeconomic Status Questionnaire, Family Assessment Device, Perception of School Climate Questionnaire, Adolescents’ Peer Victimization Questionnaire, Children’s Depression Inventory, and Adolescents’ Delinquency Index Questionnaire. Structural equation modeling showed that: (1) After controlling for gender, age, socioeconomic status and family functioning, school climate significantly predicted adolescents’ delinquency and depression; and (2) Peer victimization mediated the relationship between school climate and adolescents’ problem behaviors. In conclusion, this study has documented the importance of school climate in adolescent problem behaviors, as well as the mediating role of peer victimization between school climate and problem behaviors. The results suggest that the school administrators and educators should pay attention to the important role of school climate in adolescent problem behaviors, because positive school climate can reduce peer victimization experiences, which in turn reduce adolescent problem behaviors.