The aim of this paper was to make clear the basic points of view to bring up the "social-conventional" concepts in elementary school children. According to Turiel, E., we investigated the conciousness of social rules of children in the moral classes, and analysed their opinions of social rules. The results were as follows. 1) There were different understandings about social rules between the children in the second grade and sixth grade. The second grade children understood that social rules were necessary to keep their friend's school life safely. And sixth grade children understood, adding to the above, that social rules were formed by the consensus of their opinions. 2) To bring up "social-conventional" concepts, it's needed for teachers to fit with children's development.