Abstract: ObjectiveTo evaluate the effects of a lecture intervention on contraceptive knowledge,attitude,and behavior among university students and to provide evidence for health promotion in colleges and universities.MethodsA total of 9 203 students were selected from eight universities,of which 4 215 had a lecture on contraceptive know ledge and 4 988 had no intervention.A questionnaire survey on contraceptive know dedge,attitude and behavior was conducted before and after the intervention among the students.ResultsBefore the intervention,there were no significant differences in the scores of contraceptive know ledge and attitude between the students with and without the intervention(58.4±14.15 vs 45.7±14.22, 74.54±11.42 vs 74.78±11.13;P>0.05 for all).After the intervention,the score for contraceptive konw ledge in the students with the intervention was significantly higher than that of sdudents without the intervention(63.1±15.56 vs 59.20±14.83,t=13.40;P<0.001).The prevalence of sexual behavior in past six months was significantly higher in the students with the intervention compared to that of students without the intervention(11.46% vs 5.28%,χ²=111.09, P<0.001),but the incidence of accidental pregnancy was significanfly lower for the students with the intervention compared to that of without the intervention(12.26% vs 22.76%,χ²=12.42,P<0.001).ConclusionThe lecture inervention on contraceptive know ledge and attitude could improve contraceptive know ledge and lower unplanned pregnancy rate among university students.