Abstract: With the diversification of sale mode and the intensification of multi-channel competition, many traditional dealers and distributors have fallen into the operation bottleneck and gradually transformed to agricultural services. The growth of the service market promoted the service mode innovation of agricultural product sale.However, as a useful supplement to the distribution mode, the commission sale mode is rarely adopted in the cooperation of production and marketing for agricultural products in China.In view of the fact that commission mode specifically includes pay service feemode and regarded as buyout mode, so it is an important decision for the manufacturer and the affiliate to decide which mode to sell the products and under what conditions to reach the consignment agreement. To this problem, under the assumption of preservation efforts affecting the freshness and loss, two stackberg game models are constructed with pay service fee mode and buyout mode, then some comparative analysis are taken about the optimal prices, commission periods and preservation effort levees. On this basis, the best selection of commission sale mode is analyzed as well as the commission agreement conditions for the producers and affiliates.The conclusion shows that the service fee and negotiated price are the key factors influencing the commission strategy.If the negotiated price is high enough, the producer and the affiliate are inclined to adoptthe pay service fee mode; If the negotiated price is in the middle level, the producer and the affiliate tend to adopt the regarded as buyout mode;If the negotiated price is too low, the producer and the affiliate can not reach a consignment agreement, but the outcome of negotiation is more likely to approach the regarded as buyout mode.In addition, both service fee contract and negotiated price contract cannot coordinate agricultural supply chain.

Key words: commission sale, agri-food supply chain, preservation effort, stackberg game