The purposes of this study are to research the relation between the leader behavior of basketball coaches and team cohesion in Taichung elementary school. The results were as follows: 1. On perceiving coaches' leader behavior, the average score in order is training and guiding behavior, concern behavior, reward behavior, democratic behavior and authoritative behavior. 2. In the gender aspect, male players feel more ”training and guiding behavior”, ”democratic behavior” and ”concern behavior”. In the training time aspect, players feel more about coaches' leading behavior when they take longer training time. In the grade aspect, players who study in the higher grades feel more ”training and guiding behavior”, ”democratic behavior” and ”concern behavior”. In the time being together with coach aspect, players who are being together with coach longer feel more ”training and guiding behavior” and ”reward behavior”. In the school type aspect, players who study in the medium school feel more ”training and guiding behavior”, ”democratic behavior”, ”concern behavior” and ”reward behavior”; 3. On perceiving team cohesion, the average score in order is team adaptation, team cooperation, interpersonal attraction, and interpersonal compatible. 4. In the gender aspect, male players have higher score in interpersonal compatible. In the training time aspect, players have higher score in team cohesion when they take longer training time. In the grade aspect, players have higher score in team cohesion when their grade are higher. In the time being together with coach aspect, players' team cohesion have no difference. In the school type aspect, players who study in the medium or large school have higher score in team cohesion; 5. In the coaches' leader behaviors, training and guiding behavior, democratic behavior, concern behavior and reward behavior are positively and significantly related to team cohesion, and concern behavior is the highest related to team cohesion. The authoritative behavior is not significantly related to team cohesion; and 6. In the coaches' leader behaviors, ”concern behavior”, ”training and guiding behavior” and ”reward behavior” can predict team cohesion effectively. ”training and guiding behavior” and ”democratic behavior” can predict team cooperation effectively. ”concern behavior” and ”training and guiding behavior” can predict interpersonal compatible effectively. ”concern behavior” and ”training and guiding behavior” can predict team adaptation effectively. ”concern behavior” , ”training and guiding behavior” and ”reward behavior” can predict interpersonal attraction effectively.