Objective: To provide empirical evidence on the effectiveness of comprehensive sexuality education (CSE) on sexual knowledge and sexual attitudes improvement among college students. Methods: Sexual knowledge and attitudes questionnaire survey was implemented among college students in Beijing, who later received the CSE for a full semester. Sexual knowledge and attitude were evaluated after intervention and were compared with control students. Results: The average score of sexual knowledge was low among college students in Beijing. Most students held neutral attitudes towards "AIDS community" and "masturbation behavior" and positive attitudes towards "LGBT"(58.85%, 68.75%, 61.98%). Compared with the control group, after one semester of CSE curriculum intervention, the average scores of the five dimensions on sexual knowledge in the intervention group was significantly improved(11.79±1.16, 9.36±1.23, 4.84±0.88, 4.91±1.00, 5.35±1.03)(t=11.25, 15.74, 10.37, 5.59, 8.17, P<0.01), and the attitudes towards "sexual minorities", "AIDS communities" and "masturbation behavior" were also significantly improved(30.59±3.91, 17.70±3.41, 10.12±2.17)(t=5.16, 5.83, 2.97, P<0.01). Conclusion College students’ knowledge of sexuality is not optimistic. The attention to proper sexual attitudes is in great need. Systematic and comprehensive sexuality education curriculum could improve college students’ sexual knowledge and attitudes.