In the eco-industrial park,imitating the operational pattern of natural ecosystems,many relevant enter-prises cluster together and one firm's by-product maybe another firm's raw material.Thus,the eco-industrial chain comes into being.The structure of the eco-industrial chain is a critical factor to the stability and sustain-ability of the whole system.Focused on the structure of the eco-industrial chain,this paper conducts a research on the structure model and analyzes its characteristics,and then the resutlts maybe useful for the establishment of EIP in China.