Abstract: A charaeteristic food chain in an agro-ecosystem was constituted by three production processes: cultivating mushroom with rice straw, feeding earthworm with mushroom residues and raising broiler with earthworm. In this paper, the input of auxiiary energy and the conversion efficiency of nitrogen and energy in each joint of food chain were calculated from the data of experiment and investigation. The situation of nitrogen and energy flows in the food chain was described and evaluated and was compared with other utilization ways of rice straw.