The purpose of this study is to analyze the effects of cooperative learning on Academic Learning Time in Physical Education (ALT-PE) in elementary physical educaion class and to provide information for increasing ALT_ PE in physical education . For this research, we executed cooperative learning and traditional learning in 5 th grade and 6th grade elementary children (6 boys and 3 girls) for six weeks, and compared and analyzed the results. The tool used in observation was ALT PE supervision program developed by yoon Myeong hee(1991). The results of this study are summarized as follows: First .in teaching activities, time spent inknowledge was reduced significantly but time spent in management was similar. Second, in learners behavior time spent in activities. moving and off tasks increased and time spent in waiting was reduced. Third, ALT PE increased ignificantly in the group to which cooperative learning was applid. In conclusion, the results of this study suggest that cooperative learning increases ALT PE and improves students\' academic achievement in elementary physical education classes.