The paper studies succession of energy on modern agro-ecosystem as a case in Quzhou county,Hehei province,and the result indicates as follow: the energy input and output annually presents the increasing trend with chemic-petrolic energy being main in energy input structure and the utilization of groundwater being main in the input of the increasing environmental resource;total energy output structure becomes gradual planting output energy being leading into the integration of farming and animal husbandry with the development of forestry andfishery,besides the variety is reducing to farming and animal husbandry;the development of agriculture is in better level and hold better potential,but the increment on efficiency of energy output decreases with systemic structure being unreasonable and the decreasing predominance degree of the system,it is main reason that the proportion of forestry and fishery energy output is lower.