Objective To study the situation of exposure to sexual content in mass media among middle school students, their communication with parents, peers and school teachers about these sexual content they exposed to, and their perceived parents' attention on different types of media that they exposed to. Methods An anonymous computer assisted interview survey about the situation of adolescents' exposure to sexual content in different types of mass media was conducted among 1 403 senior and junior high school students, 668 cases of junior middle school students and 722 cases of senior middle school students were included. Results Among different types of sexual content that respondents exposed to, dating/marriage, sexual intimacy behaviors between opposite sex, puberty development and consequence of unprotected sex accounted for higher percentage, varied from 37.4% to 88.2%, while contraception and STIs/AIDS accounted for lower percentage, varied between 13.5% and 37.3%.The percentage of exposure to different types of sexual contents in mass media was higher among senior high school students than junior high school students, and was higher among male students than female students, except on dating and consequence of unprotected sex, all these differences were statistically significant (P<0.05).When exposed to these sexual contents, respondents mainly chose to talk with classmates/peers rather than parents/teachers, and the percentage among senior students(61.6%~74.7%) was higher than that among junior students(33.2%~48.7%), the difference was significant(P<0.05).On the aspect of perceiving attentions from parents on media exposure, senior students' parents paid lower attention to children' exposure to types of media than that of junior students' parents and the differences were statistically significant(P<0.05).In addition to, respondents perceived that father paid lower attention than mother on the media they exposed to. Conclusions Exposure to sexual content is common among middle school students in Shanghai, China.School and family should react actively, conduct media literacy education to help adolescent learn how to deal with the sexual information in the media, especially among senior high school students.