Based on the game theory, coordination contract of closed-loop supply chain was studied. The results show when under symmetric product cost information, coordination can be achieved by setting a profit sharing coordination policy. Under asymmetric product cost information, if exogenous parameters satisfy some certain condition, only the above-mentioned coordination policy can achieve the supply chain coordination. Otherwise, retailer can set the profit sharing proportion as the function of announced cost by the manufacturer. This strategy can make the closed-loop supply chain coordinative.