Nowadays, the market competition is among the supply chains rather than among the enterprises. In the supply chains, the information sharing, the replaning period and their interactions all have impacts on the supply chain performance. In this paper the study on the impact of the information sharing, replanning interval on the performance of a supply chain with one capacitated manufacturer and four retailers was presented. A computer model was developed to simulate the supply chain. The object-oriented C++ language was used to process the simulation program. The production status, the inventory status and the sale status were observed in the process of the program simulation. The output from the program were analyzed by the statistically software, to get the conclusion.