Abstract: The problem of incenting producer to reduce product’s cost under asymmetric information condition is discussed Under asymmetric information condition,manager can’t observe producer’s efforts on reducing cost,so it is necessary to incent producer for manager Manager determines a contract base according as his request and producer’s self-offered,and the model which maximize manager’s expect utility under the condition of individual rationality and incentive compatibility constraint is given,and the decision variable are Encouragement multiple and punishment multiple The evolutionary programming algorithm is used to do the simulation.

Key words: asymmetric information, moral hazard, principal-agent theory, Cost