Abstract: The U.S.A. is the largest producer and exporter of agricultural products in the world and its agricultural policy changes have a significant impact on world agricultural market. This paper summarized the evolution of U.S.A. agricultural policy and analyzed the changes of policy support level. The results showed that the U.S.A. policy support level increased but producer support decreased and the level was below the Chinas 4 major producer subsidies. The U.S.A. subsidy was mainly concentrated on bulk products and the bigger farm got more subsidy.

Key words: agricultural policy, subsidy, farm bill