中文摘要：

利用合同理论的方法，借鉴类似回购合同的假设，研究“制造商一零售商”二级供应链中3种不同质量水平的产品回收最优定价问题，以最大化零售商、制造商和供应链的利润。该闲环供应链中只有一个制造商和零售商，零售商负责产品的回收。从分析可知，通过调整参数值，在回收率确定或随机的情况下供应链都可以达到协调，也都可以找到最优订货量和回收价格。研究发现，零售商的最优价格与最优订货量紧密相关，制造商的回收价格并不影响供应链的总体利润。

英文摘要：

There are three types of recovery mode because of extended producer responsibility, which are producer recovery, outsourcing and joint recovery. Recovery by producers assisted by retailers is a typical, effective outsourcing recovery mode. In this paper, we focus on how to determine the optimal buyback prices of recycled products with different quality in the ＂manufacturer - retailer＂ two-level supply chain, in order to allow manufacturers, retailers and supply chain to maximize their profits. To do that, we use the contract theory, draw on a similar assumption of buy-back contracts and assume there are three types of quality degree of reeyclable products in the closed-Loop supply chain, and there is only one manufacturer and a retailer and the retailer has been in charge of recycling products sold. The results show that by adjusting the parameter values, no matter the recovery prob- ability is random or not, circumstances of the supply chain coordination can be achieved. We also can find the optimal order volume and recovery price. And we also see that the optimal retail price is closely related to the optimal order quantity, the manufacturer＇s optimal price does not affect the overall supply chain profit.