By review and analysis the researches of school moral atmosphere conducted by researchers abroad and home, we found there is still apparent limitations and blanks in this fields, and it is necessary for us to in-depth study in this field .In china, researches of school moral atmosphere have much significance in the contemporary era, as well as theoretical and practical values.A group of 663 male and female students, equally proportioned by gender, ranging from grade levels of Junior One, Junior Three through Senior One of 4 high schools in various regions of the coastal area, the middle area and the western area in China, were assigned to take part in this study. One standardized instrument namely the School Moral Atmosphere Questionnaire, a project test and an experiment have been employed to collect data. A combination of quantitative and qualitative methods was used to analyze the collected data resulting from the questionnaire, project test, experiment as well as interviews.The study found that, first, students' perceptions of atmosphere of care are higher than that of forgiveness and justice. Second, there lie area differences in the perceptions of school moral atmosphere. They are higher for students from the middle area than for those from the other two areas. Third, there exist age differences in the perceptions of school moral atmosphere. Junior One students' perceptions are higher than that Junior Three and Senior Two students'. Fourth, no gender differences exist in the perception of school moral atmosphere except from their perceptions of justice atmosphere. Fifth, differences, mediated by subjects' willing, request from help seekers, teachers' request and parents' attitude, can be found between the perceptions of moral rules and school moral atmosphere in cognitive judgment, behavioral tendency and feeling. Sixth, students for all grade levels percept large number of unjust phenomena at school; Junior One and Senior Two students percept more cares than Junior Two students in class; Junior One and Junior Three students percept nearly no forgiveness, vice versa for Senior Two student. Finally, the training of students' perceptions of justice atmosphere and care atmosphere are proven to be effective and the two intervening ways of context discussion and role playing are shown to significantly enhance students' perceptions of care, justice and forgiveness atmosphere.