Abstract: ObjectiveExploring the factors thathave a close relation with sexual behaviour to ummarried youhts,so that teaching them in reproductive health.MethodsWe formulate a questionnaire about reproductive health among 1600 unmarried youhts.The questionnaire has 83 problems in 5 aspects.In this article,we choose 21 variables and analyze it by means of canonical correlation.ResultsThe male youhts,who have had love affairs, and think that sexual intercourse is rational in the period of love, have a close relation with sexual illusion and sexual intercourse.ConclusionThe unmarried youhts should not love too early.The emphasis of education of reproductive health is male youhts.