Abstract: The developing course of eco-economic system is measured off 4 stages. Zhifanggou valley has been in third stage at present. In analyzing development driving force of a different of stages eco-economic system, the author discuss the developing laws of eco-economic system structure of ecological economy produce systematic function of ecological economy and human development which the aftereffect of ecological system act on economic system, systematic may adjust systemic structure of ecological economy according to human’s need,and the devotion main body of eco-economic system is different form in different developing stage. Finally the author discusses the incorporating form of eco-economic system development in the project of fading cropland and returning forest (grass). The actualizing area of the project of fading cropland and returning forest (grass) will be in the evening of second stage or the third stage.