Weiquan Du,1 Zhaoyuan Fan,1 Diankun Li,2 Mingshuang Wu1 1School of Sociology and Population Studies, Nanjing University of Posts and Telecommunications, Nanjing, People’s Republic of China; 2School of Economics, Nanjing University of Posts and Telecommunications, Nanjing, People’s Republic of ChinaCorrespondence: Weiquan Du, School of Sociology and Population Studies, Nanjing University of Posts and Telecommunications, No. 9, Wenyuan Road, Nanjing City, 210023, People’s Republic of China, Tel +86 13451870628, Email duwq@njupt.edu.cnPurpose: This study focuses on how Internet use behavior affects adolescents’ mental health and whether self-education expectations and parental support mediate the relationship between Internet use behavior and adolescents’ mental health.Methods: The data for this paper came from the results of the student questionnaire of the 2018 Programme for International Student Assessment (PISA 2018), which was a structured questionnaire that asked students about their family situation, school life, studies, internet use, and mental health, among other things. A sample of 336,600 children in grades 7– 13 was selected for this study. The data were analyzed using STATA version 16 and the theoretical framework was tested using a mediated effects model.Results: The results of the study showed that Internet use behavior made a positive contribution to mental health and the mediating effects of self-education expectations and parental support on the relationship between Internet use behavior and adolescent mental health were all significant.Conclusion: It is recommended that appropriate policies should be formulated to help adolescents use the Internet rationally, and the positive effects of parental support and self-education expectations should be utilized.Keywords: adolescent, mental health, internet use, self-education expectations, parental support