Abstract: The establishing of China_ASEAN free trade area, the development of western agriculture will face to challenge with opportunity. The readjustment of structure is an important measure to reply China_ASEAN free trade area for agriculture in western. want to make good the readjustment of structure for agriculture , western must determine the principle and the direction of readjustment of structure for agriculture base on the circumstance , at the same time, government take measures to support the readjustment of structure for agriculture .