This research analyzed daily students' behaviour during recess between classes in middle school with subject centre system. The purpose of this research is to explore better school design for students. The study found unique behaviours that students formed 3 to 4 groups and each group went in and out of their homebases because of adjustment to congestion of the homebases. In addition, these students' behaviour between classes were influenced by other grades. The study clarified that students tend to form their comfortable environments being conscious of the relations with other students using a time-lag and movement-lag.