Objective To investigate the current situation of internet addiction among adolescents in Minhang District， Shanghai， and analyze the risk level of internet addiction among adolescents of different school stages and genders. Methods From April to May 2023， students in the third and/or fourth grades of three primary schools， one second grade of junior high school， and one first grade of high school in Minhang District， Shanghai were selected as the research subject by cluster random sampling method. This study collected general information of adolescents and compared the differences in internet addiction among adolescents of different school stages and genders using the Revised Chen Internet Addiction Scale （CIAS-R）.Univariate and ordered Logistic regression were used to analyze the risk factors of adolescent internet addiction. A total of 1 284 questionnaires were distributed offline， and 1 044 valid questionnaires were collected， with a valid response rate of 81.3%. Results In the adolescents， the total detection rate of internet dependency was 5.9% （62/1 044）， and the total detection rate of internet addiction was 2.9% （30/1 044）. The detection rate of internet dependency among primary school students was 4.0% （27/672）， and the detection rate of internet addiction was 1.6% （11/672）. The detection rate of internet dependency among middle school students was 9.4% （35/372）， and the detection rate of internet addiction was 5.1% （19/372）. There was a statistically significant difference in the level of internet addiction among primary and middle school students （χ2 =23.816， P＜ 0.001）. There was no statistically significant difference in the level of internet addiction among adolescents of different genders （P＞ 0.05）. There were statistically significant differences in the total score of CIAS-R， the scores of the core symptoms of internet addiction subscale， the scores of the internet addiction related problems subscale， and the scores of the four factors among adolescents of different school stages and genders （all P ＜ 0.05）. In the primary school students， there were statistically significant differences in the level of internet addiction， total CIAS-R score， two subscale score， and four factor score among adolescents of different genders （all P ＜ 0.05）. In the male population， there were statistically significant differences in the total CIAS-R score， two subscale score， and four factor score among adolescents from different school stages （all P＜ 0.05）. In the female population， there were statistically significant differences in the level of internet addiction， total CIAS-R score， two subscale score， and four factor score among adolescents of different school stages （all P＜0.05）. Logistic regression analysis showed that middle school stage was a risk factor for adolescent internet addiction ［OR=2.852， 95%CI=（1.842， 4.410）， P ＜ 0.001］. Among primary school students， male gender was a risk factor for internet addiction ［OR=3.593， 95%CI （1.622， 7.956）， P=0.002］. In the female population， middle school stage was a risk factor for internet addiction ［OR=7.106， 95%CI （3.152， 16.023）， P ＜ 0.001］. The above differences were statistically significant. Conclusions The level of internet addiction among primary and middle school students in Minhang District， Shanghai is the highest among male and female students in middle schools， followed by male students in primary schools， and female students in primary schools have the lowest level of internet addiction.