This study investigated the developmental pattern of domain distinction between three age groups ; high school students, college students and their parents. Previous research illustrated that with increasing age, definitely some kind of change is occurring in subjects' judgments of domain in a given moral situation. That is, the criteria of judgment or conceptualization of domain is gradually changing from the focus on the moral domain to conventional or personal domain. As children become older, they become more likely to actively engage in maintaining the social order of established social institutions. The hypothesis is that more adolescents will have moral domain judgment than adults. Conversely, more adults may have conventional or personal domain judgment. The result was that more college students were using the moral domain than high school students and their parents. Discussions were made about the influence of college life, and the developmental feature of moral domain judgment; during high school and college years the moral domain judgments were increased and then after college years they were decreased. Further investigations need to identify the factor that initiate the conventional or personal domain judgment.