中文摘要：

在二层信用条件下，建立零售商相关成本极小化的多物品经济生产量模型，讨论模型最优解的存在性、唯一性以及寻求方法，并用具体的数值例子验证模型的有效性．

英文摘要：

An EPQ model is developed to minimize relevant cost of retailer for multi-item under the condition of two levels credit trade. The existence and uniqueness of the optimal solution to the present model are discussed, and numerical examples are given to illustrate the developed model.