Objective: To understand the current situation regarding sex education in home and school settings in China, and to provide a scientific basis for more effective family and school sex education. Methods: Using a convenient sampling method, a crosssectional survey of students from grade 7 to grade 9 in Beijing, Liaoning, Sichuan, Chongqing, Yunnan and Henan was carried out from September to December 2021. The questionnaire covered general demographic information, sex education at home and school, and the status of comprehensive sexuality education. Finally, 4 109 valid questionnaires were collected. Results: A total of 760(18.50%) middle school students had not received any form of sex education, 923(22.46%) had only received sex education at school, 299(7.28%) had only received sex education at home, and 2 127 (51.76%) had received sex education at home and at school. The scores related to junior middle school students knowledge of comprehensive sexuality education was (12.43±2.89) points, the attitude score was (47.86±5.31) points, the behavior score was (40.44±5.18) points, and the comprehensive level score was (82.02±9.01) points. Junior middle school students who received sex education at home and in school had the highest comprehensive level of sex education( P <0.01). Junior middle school students who only received sex education at school had a higher comprehensive sexuality education knowledge level than those who only received sex education at home( P < 0.01 ). The level of comprehensive sexuality education behavior among junior middle school students who only received family sex education was significantly higher than among those who only received sex education at school( P <0.01). Conclusion Receiving sex education in both home and school settings can effectively improve the comprehensive sexuality education competency among junior middle school students. School based sex education should be further implemented in the future and family sex education should be encouraged.