Abstract: [Objective] The paper studies some problems in supply-market system of under forestry economy, designs trading mode with contract theory and sets up under forestry products supply chain, which will provide reference for the development of under forestry economy.[Method] A two-level supply chain model with single vendor and many producers is established, and market demand function, the mean profit of producers and vendor are calculated. The function model can also be used to compare and analyze producer's profit, vendor's profit and system efficiency under different trading decision model.[Result] 1) Under the disperse policy decision and non-contract model, producer and vendor always make their decision on the basis of their profit expect, which may lead to much system losses, low consumer welfare and low efficient system. 2) Under centralized decision-making and non-contract model, we can improve obviously the system efficiency,and provide more products to the market with ensuring customer welfare. But the supply chain is not very stable, and the producers like to break a contract. 3) Under revenue share contract model, the profits of both sides will be protected. But the bad effect is that vendor does not like to sign the contract, because profit of vendor cannot be protected by many unpredictable factors. 4) Under constraint and revenue contract model, profits of both sides will be protected through adding constraint condition, which can help to realize the original goal to manage the supply chain of under forestry economy products.[Conclusion] 1) The new-designed model will change producing pattern with supply chain management under sharing contract, which can improve risk resistance capability, deduce decentralized operation of under forestry economy products supplying and marketing system. 2) It is an effective measure for producer and vendor to sign sharing contract, which can protect both sides profits and help them get more profits. 3) It is also beneficial for the supply chain of under forestry economy products to perfect the rule of sharing contract. The paper has given some advice basing on the result:1) All participants and government need to improve cognition for the under forestry economy products supply chain management. And then all of these suggestions can be built and managed in coordination situation. 2) By designing and optimizing supply chain under sharing contract, the supply chain will work effectively. 3) With supporting measures by government, it will ensure smooth development for under forestry economy products supply chain. 4) Precautions against should be taken by developing marketing mechanism.

Key words: under forestry economy, under forestry products supply chain, revenue sharing contracts, supply chain coordination(SCC)