According to Korean Civil Code § 909, parents have parental responsibility for their child where they are married to each other, but when they are divorced, they can make an agreement chat only one of them has parental responsibility. If they can nor come to an agreement, they can request a court select one of them to have parental responsibility. And for a illegitimate child, mother has parental responsibility without putative father`s acknowledgement. But when he acknowledged his child, parental responsibility can go to him by an agreement with the child`s mother or a decision of a court. Korean Civil Code does not give any preference to father or mother in respect to parental responsibility for legitimate child or illegitimate child. But after divorce it is preferred that one of parents has parental responsibility, as is the same as for illegitimate child. This paper insists on it that parental responsibility after divorce has to go to both of parents such as parents are married each other, and argues [hat for illegitimate child, only mother has to get parental responsibility without an agreement between parents or a decision of a court. In case of adoption, especially when a spouse adopt a child of other spouse, they must commonly adopt the child to have parental responsibility. When a decision is made that one of parents has parental responsibiity, it is ruled by welfare principle.