Abstract: This paper analyzed the condition of agricultural self-enforcing contract，which was based on the substitute transaction cost and asset specialty in the relaxation of the assumption of bilateral monopoly. The higher of substitute transaction cost and the extent of asset specialty, the wider of the self-enforcing contract price interval. The bargaining power was the decreasing function of substitute transaction cost and extent of asset specialty. These conclusions explained the low performance of order agriculture, and provide the theory basis for the development of agricultural industrialization.