In contractual relationships involving payments for environmental services,conservation buyers know less than landowners know about the costs of contractual compliance.Landowners in such circumstances use their private information as a source of market power to extract informational rents from conservation agents.Reducing informational rents is an important task for buyers of environmental services who wish to maximize the services obtained from their limited budgets.So reducing informational rents also mitigates concerns about the “additionality” of PES contracts.Counting opportunity cost have high influence to compensate standard and region,which is not only a core issue of PES,but also a nodus of based PES mechanism.This paper take the approache of gathering information from costly-to-fake signals to reduce informational rents,we using multianalysis to simulate opportunity cost which converse feed to fast in Gannan District,then distinguish opportunity cost types to make high-landowners can get more compensate than low-cost landowners,therefore conservation buyers can get more environmental services.