An influence diagram is a kind of graphical model that can represent both the probabilistic relationship between variables and can easy to make decisions. It can make full use of Bayesian Network and Decisiton Tree. Influence Diagram should be modify to inprove the effiency to express relationships among variables. Extensional model of Influence Diagrams is introduced in this paper to express the new kind influence diagrams. And this kind of new model can be applied in the area of supply chain management.