Purpose: This study was done to examine the relationship between sexual permissiveness, family function and parent-adolescent communication among adolescents. Method: A descriptive correlation approach was used and the participants were 956 male and female students. Data were collected by questionnaire survey using convenience sampling. The instruments were the Family APGAR Questionnaire by Smilkstein(1978), PAC by Olson and Barnes(1982), and the Premarital Sexual Permissiveness Questionnaire by Reiss(1967). Data were analyzed using the SPSS 10.0 program with descriptive statistics, Pearson correlation coefficients, t-test, and ANOVA. Results: Family function was significant according to school record, economic status, living arrangement of parent. Parent-Adolescent Communication was significant according to religion, economic status, having a boy/girl friend, and experience of sexual intercourse. Sexual permissiveness was significant for all except economic status. Correlation among the variables showed that parent-adolescent communication was negatively correlated to sexual permissiveness(r=-.127, p=.000) and positively to family function(r=.368, p=.000). Conclusion: The findings suggest that parent-adolescent communication and family function are associated with sexual permissiveness, and the findings of this study are expected to make a contribution to creating an ideal sexual culture for youth.