Abstract: Objective To investigate the prevalence and the association between Internet addiction and suicide behaviors among middle school students and to explore whether the association could be partly or fully accounted by depression and bullying behaviors.Methods Using two-stage random stratified cluster sampling,3 229 students were recruited in Guangzhou city and an anonymous survey was conducted among the students with a self-designed adolescent health knowledge questionnaire,Young Internet Addiction Test,The Center for Epidemiological Studies Depression Scale (CES-D) and Olweus Bully/Victim Questionnaire.Logistic regression was used to explore the relationship between Internet addiction and suicide behaviors.Results Of the 3 229 eligible respondents,14.70% reported the Internet addiction and 20.70% and 3.96% reported suicide ideation and attempt during the previous 12 months.After adjustment for potential confounding factors,Internet addition was associated with suicidal ideation (OR =3.88,95%CI:3.04-4.96) and attempt (OR=2.42,95%CI:1.41-4.13).When depression and bullying behavior were entered into the regression model,the odds ratios of suicide ideation declined to 2.58(95%CI:1.99-3.34),while the association between Internet addition and attempt was insignificant.Conclusion Adolescent Internet addition is associated with suicidal ideation and attempt,and the association is possibly mediated by depression and bullying behaviors.