Abstract: Objective To examine prevalences of smoking, alcohol drinking and bullying among middle school students in Guangdong province and to explore the relationship between smoking, alcohol drinking and school bullying.Methods Random stratified cluster sampling was applied to select 20 718 middle school students in six cities in Guangdong province and an adolescent health knowledge questionnaire was used for an anonymous survey.Results The current smoking prevalence in the middle school students was 4.5%and the current alcohol drinking prevalence was 20.5%, with a coexistence prevalence rate for smoking and alcohol drinking of 3.0%.The detection rate of bullying was 12.9%.School bullying was significantly associated with smoking and the interaction between smoking and alcohol drinking on school bullying was significant.Conclusion The smoking and alcohol drinking behavior are not rare among middle school students in Guangdong provine and significantly associate with the incidence of school bullying.