Abstract: For the quantity flexibility contracts about perishable product's supply cooperation, we construct ted two models based on different options in stochastic market demand condition. By analysis, we gain retailers' order policies about different options. In the policies, retailers' option-order quantity is smaller, initial order is bigger, and total is smaller in the contract based on bidirectional options than in the contract based on unilateral options. The optimal total quantities in two different option contracts are bigger than the quantity in the traditional contract. The two option contracts can all improve retailers'total order quantity, but they are different their quantities approach the optimal supply chain order quantity in a given contract parameter.

Key words: supply chain, unilateral options, bidirectional options, contract comparison