Abstract: This paper a bilevel prog ramming problem which assumes that the interaction between suppliers and distributors will be pursued to maximize the objectives and the user needs.In the model,the upper planning is the retail price optimization models for uppliers and distributors,the lower model is the equilibrium between purchase and dem and for the user.Such as various information sharing mechanisms for oligopoly,monopoly,social optimum,which reflects the needs in supply chain,responds to the upper pricing behavior.The paper designs sensitivity analysis algorithm and iterative method for solving and optimizing the problem of need equilibrium in supply chain.

Key words: logistics information sharing, value-adding mechanism, demand equilibrium, supply chain management, bilevel programming