AbstractAccording to the industry ecology theory, in the simulating flowing way between substance and energy in the nature ecology, to design the industrial production systems can use less resource reasonably and reduce emissions. As the most important large iron & steel enterprise in Inner Mongolia, applying the theory of industrial ecology, the Baogang Group gains great achievement in energy saving and emission reduction in recent years. Based on the industrial ecology theory, this paper mainly analyzes the practice of energy-saving and ejection-decreasing of the BaoGang Group.