[Objective] The objectives of this paper are to discuss the evolutionary process of agricultural eco-economic system from 1986 to 2013 at Wangdonggou watershed in gully region of Loess Plateau, analyze coupling status between agriculture system and eco-economic system in different development stages in order to provide support for economic and social sustainable development of the region. [Methods] Based on the long-term monitoring data and agricultural household survey at Wangdonggou watershed in gully region of Loess Plateau, we established agricultural eco-economic system comprehensive evaluation indices, and analyzed coupling situation in the process of agricultural eco-economic system using a coupling model. [Results] (1) The composite evaluation index of agricultural ecosystem and agricultural economic system increased from 1986 to 2013 at Wangdonggou watershed; (2) The agricultural eco-economic system had underwent recovery phase, harmonious development phase and reconversion phase, and the current coupling status was harmonious development phase. [Conclusion] In the evolutionary process of agricultural eco-economic system, it could develop efficiently and stably through optimizing agricultural resources and finding new growing point.