Objective To explore the correlation between internet use and emotional state of junior middle school students, and to know influencing fators on internet overuse. Method A total of 825 urban and rural junior middle school students were investigated with general condition questionnaire, The Screen for Child Anxiety Related Emotional Disorders ted with (SCARED), Depression Self-Rating Scale for Children (DSRSC) and Internet Self-Rating Scale. Results It checked out 44 students overusing internet, and the detection rate was 5.33%.The difference between boys and girls was significant (χ²=10.39, P=0.002)[32 boys(3.88%), 12 girls(1.45%)].There was obvious emotion difference between internet overusing and no-overusing.The anxiety and depression in internet overusing group was serious than that of no-overusing group (P<0.01).Correlation analysis discovered that totle scores of internet use were closely related with anxiety, depression, grade, age, gender, parents culture etc.Multiple regression analysis showed that school terror, depression, father culture, gender and so on were dangerous influencing factors on overusing internet. Conclusion Much attention should be paid to internet overusing issue of junior middle high school students.Internet overusing and emotional disorder are significantly related, with emotional disorder, low culture of father, boy students are risk factors on overusing internet.