A case from a private enterprise was studied to deduce the factors of affecting cohesion and the relationship between those factors and cohesion.  It is suggested that there are two new factors: the private relationship among TMT members and the ways of motivation. Through the qualitative analysis,it was summarized that the influence of age diversity to cohesion is inconspicuous,the affecting of personality heterogeneity is significant negative,and the influence of experience diversity is positive; the negative relationship between affective conflict and cohesion in China is a little slighter than in western countries,while the team headship can influence the team cohesion; the private relationships-based team has more strong cohesion and  is benefit to the team cohesion using shares to motivate members.