This study was done to identify sexual knowledge, sexual attitude, and parent efficacy among parents of preschool child. Participants were 70 couples, parents of preschool child. Data were analyzed using chi-square test, t-test, ANOVA. The difference in recognition and attitude about sexuality education for children among parents, person in charge of sexuality education for children(p=.043), parents' experience of sexuality education for their children(p=.043), the number of communication about sexuality with their children(p=.019), the source of information about sexuality(p=.024) showed significant difference. Sexual knowledge(p=.018) and sexual attitude(p=.006) showed meaningful difference. As a result of this study, it is necessary to develop and conduct differentiated education programs when teaching parents about sexuality education for their children in preschool period, considering these characteristics.• Key Words : Sex education, Parent, Preschool child, efficacy, Sexual knowledge, Sexual attitude