Using the methods of expressing overconfidence provided by Daniel,Hirshleifer,Subrahmanyam,Gervais and Odean etc.for reference,this paper researches the equilibrium of team coordination under the condition when overconfidence and external monitoring co-exist, and the mechanism of overconfidence and external monitoring effects on team coordination by setting up an appropriate mathematical model.The result shows that overconfidence of team agent and external monitoring are substitutes rather than complements ...