Abstract: Objective To learn status and influential factors of internet addiction disorder of Yi and Han junior middle school students in Panzhihua City. Methods Students were selected from Dahe and Minzu middle schools in Panzhihua City by stratified cluster random sampling to investigate internet addiction disorder through self-designed questionnaire. Chi-square test, rank sum test and logistic regression were used to explore influential factors of internet addiction disorder of the students. Results A total of 1 000 questionnaires were distributed and 963 were recovered (recovery rate, 96.3%). Excluding 63 neither Han nor Yi students, the valid questionnaires were 900 (416 males and 484 females, averagely aged 13.4 years), of whom 628 were Han students and 272 were Yi students. The rates of internet use and internet addiction of the students were 83.7% and 8.3%, respectively. The internet addiction rates were 8.6% for Han students and 7.7% for Yi students. There was no significant difference in the internet addiction rates between Yi and Han students. In the multiple logistic regression model, high level education of mother (OR=1.428), unhappy in school life (OR=1.424), bad relationship with families (OR=1.810), psychological inversion (OR=2.636), being bantered maliciously (OR=1.920), and being made fun pornographically (OR=2.240) were risk factors, while female (OR=0.412) and good achievement (OR=0.692) were protective factors for internet addiction.Conclusion The internet is in common use among students of junior middle schools and many factors are associated with internet addiction disorder. Teachers of the schools and parents of students should pay attention to the influential factors of internet addiction disorder to prevent and control the internet addiction of the students.