Abstract: To research the basic characteristics of order allocation in multilevel logistics service supply chain，the three-echelon logistics service supply chain was taken as a example to study.A bi-level programming model for three-echelon logistics service supply chain under stochastic demands was presented.And the genetic algorithm was used to solve the model.Numerical studies results demonstrated that，with the increase of uncertainty，the total cost of Logistics Service Integrator (LSI) and the general profit of Functional Logistics Service Providers (FLSPs) was increased，while the total satisfactory of all FLSPs was decreased.However，the total profit of providers as well as the total satisfactory of each subcontractor were not presented consistent increase and decrease.

Key words: three-echelon logistics service supply chains, order allocation, stochastic demand, bi-level programming

摘要： 为研究多级物流服务供应链情况下订单任务分配的基本特性，以三级物流服务供应链为例进行研究，给出随机需求环境下三级物流服务供应链任务分配的双层规划模型，并利用遗传算法进行求解。算例研究结果表明，不确定程度的增大将使物流服务集成商的总成本增大、物流服务提供商的总利润增加、物流服务提供商的总体满意度降低；但是，提供商各自的总利润却没有呈现出一致性增大或减小的特征，提供商各自分包商的总满意度也未呈现出一致性增大或减小的特征。

关键词: 三级物流服务供应链, 任务分配, 随机需求, 双层规划