Abstract: This paper discusses successful modes of forest-grassland enlargement in northwestern and northeastern regions of China in recent years and its application trend in grassland agro-ecological systems in the country. Theoretical basis for the application include eco-kybernetics which accelerates eco-system coupling and synthesis; eco-engineering which enhances production efficiency; and eco-technology which saves water and energy. Synthesis of regulation and control mechanisms of society as well as developmental functions of eco-systems and the utilization of ecological knowledge to promote natural resources protection are very crucial elements of grassland agro-ecological systems.