Abstract: Objective To describe the status of sexual behaviors and its influencing factors among college students in Nanjing,and to provide scientific reference for carrying out A IDS and sex health education.Methods A self-administered questionnaire survey was conducted among 3238 students chosen from five universities in Nanjing by cluster multistage sampling.Face to face interviewwas done in 90 students for qualitative analysis.Results 10.7% of students had sex experiences.70.0% of sexually active students did not use condom every time and 3314% had more than one sexual partner.13.5% of sexually active students or their partner had the experience of abortion.Logistic regression analysis showed that the sexual behaviors positively correlated with the urban students,senior class,art college students,logging in sexy website and approving of premarital sex(P<0.01).The qualitative results showed that though the cognition of premarital sexual behavior presented diversified trend,fewstudents recognized the relationship between the premarital sexual behavior and the health problem.Conclusion It is important to provide college students with AIDS and sex health education and behavior intervention.