Group cohesion could not only influence team's performance and outcome, but also influence team members' affects, cognitions, and behaviors. There were many factors that could possibly influence group cohesion, such as group sizes, coaches' leadership styles, satisfaction, and sport performance etc. After reviewing former researches about the effects of group size on group cohesion, This article noticed that there was no consistency between former research results, It needed to consider that former researchers ignored that group cohesion is a multidimensional concept, there was a continuous, dynamic interrelationship between group cohesion, satisfaction and sport outcome. Thus, in future studies, we must consider factors like coach leadership style, members' satisfaction, sport performance, competition level and type of sports, to make clear the relationship among factors.