The purpose of this paper was to clarify the developmental feature of contextualisum criterion judgment that Japanese students apply to distinguish social-conventional concepts from moral concepts. An investigation was conducted on students from the ages of 6 years old to 23 years old. The condition of two social-conventional violations and the condition of two moral violations were presented in a questionnaire. The children were asked if the violations were acceptable if the circumstances appeared reasonable. In addition, a groups' response was considered for examination regarding the same scenario. The results are as follows: 1) Understanding of social-conventional concepts become clear during 10 to 11 years of age and 18 to 25 years of age. 2) Changes in moral concepts occur during 10 to 11 years of age and at the ages from 14 to 16 years old, while at the same time changes stabilize between the ages of 14 to 16 years old. 3) Between the ages of 12 to 13 years old and the ages of 18 to 25 years old, students understand criterion judgment of contextualism to social-conventional concepts as relative while comprehending moral concepts as universal. In other words, students are able to differentiate between the two concepts of social-conventional and moral during these two age ranges. 4) Age had no influence in the group's standards of judgment for contextualism.