Coordinating producer and supplier is one of main issues of supply chain with uncertain delivery. Consid2 ering interaction between the members in supply chain , there is a Stackelberg game in supply chain. The nature of the Stackelberg game is discussed in this paper. The solution of the game is deduced. As the leader , the producer in supply chain initializes the optimal order quantity and penalty cost policy for minimizing his cost , while as the fol2 lower , the supplier responds with the optimal extra capacity policy for maximizing his profit . Appling genetic algo2 rithm , a simulation about tail rolled steel products is done based on Shanghai BaoSteel industry &trade co. . The solution is adopted for implementing J IT in the supply systemof Shanghai BaoSteel industry &trade co. . The simu2 lation solution shows that Stackelberg game is effective and practical .