It is usually observed in the supermarkets that display of deteriorating items. These items are with short shelf life and difficult to be transported and stored. A supply chain conceptual model which consists of one supplier and two retailers is structured. Based on analysis of deteriorating inventory model in exist, the transshipment between the two retailers is added into the supply chain conceptual model and a deteriorating model is developed in this paper which can reflect more accurately the relation among inventory level, demand rate, deteriorating rate and lateral transshipment rate. The ordering policy taking into account the shelf life constraint is investigated with two last ordering opportunities on condition that the planning horizon can be modified based on the lateral transshipment. At last, the conclusion implies that the ordering policy for deteriorating items with short shelf life based on the lateral transshipment can improve the profit for the retailer.