Abstract: Objective To unde rstand the attitude of college students in Guangzhou toward premarital sexual behavior and to provide evidence for sexual health education.Methods With straified cluster sampling,840 college students were selected and investigaed by anonymous questionnaire infour universities in Guangzhou.Results The approvab lerate of premarital sexual behavior in male students was higher than that of in female students(P<0.01).The approvable rate of premarital sexual behavior in higher grade students was higher than in low grade students(P<0.05),with a gradually increas ing trend from low grade to higher grade.There was a significant difference in the attitude toward the rationality of premarital sexual behavior with no pregnancy and the promise for love by premarital sexual behavior between the students from urban and rural a reas(P<0.05).49.7% of the students thought the sex was OK if the lovers both had love emotion.51.6% of the students thought that the premarital sexual behavior was the physiological and psychological needs.55.3% of the students thought that the premarital sexual behavior was to satisfy the sexual desire.A higher ratio of sexual experience was reported among the students with positive a ttitude toward premarital sexual behavior.Conclusion Now adays,the college students' attitude toward premarital sexual behavior is diversified.The premarital sexual behaviors exist objectively among the students.The sexual health education should be different according to different students.