Recently, a matter of the highest priority that the company must do for the satisfaction of customer service is that the company ensure the competitive power throughout the strategic cooperation in the market environment changing rapidly. In this situation, one of allied strategies is the supply chain management strategies. This paper suggests how to increase customer service and to decrease inventory throughout construction of the inventory sharing system among networked company. For this, we experimented the effect of the inventory information sharing system on the supply chain dynamics by using the simulation modeling and analyzed the validity about construction of the inventory sharing system presented in this study. The simulation is designed by Vensim(Process simulation package) and has some feedback loops.