Abstract: ObjectiveTo investigate the prevalence of internet addiction disorder(IAD)and its related factors,especially psycho social factors among high school students.MethodsThe study was conducted among 736 high school students in Deqing county,Zhejiang province.Self administered questionnaire,Internet Addiction Test(IAT),Chinese version of Emotional Warmth,Rejection and Protection(EMBU),Coping Style Scale for Middle School Students,Stressor Scale for Middle School Students,and Symptoms Check list 90(SCL 90)were adopted.ResultsThe rate of IAD among the students was 9.8%,and the rate in male students(12.2%)was higher than that of in female students(7.3%,P<0.001)The rate of IAD increased with the increment of online time per day(P<0.001).Multiple logistic analysis showed that study stress(odds ratioOR=1.101),schoolmate and friend stress(OR=1.649),avoidance(OR=1.134),fantasy(OR=1.171), psychotic disorders factor of SCL 90(OR=2.180),on line time(OR=2.716),and over intervention from father (OR=1.068)were significantly related with total score of IAD.ConclusionIAD may relate with sex,online time,stress, coping style,and parental nurturing style,and personality character among high school students.