Based on the principle of carbon balance, a model was built to calculate CO 2 emissions of each process and correspondingly the total course of production in iron and steel making. The data from a typical integrated steelworks in China was applied in the model. The results show that the BF and coking process account for the most emissions. Generally, CO 2 emissions in integrated steelworks depend on three factors, resources utilization efficiency, energy utilization efficiency and energy consumption structure, which were considered in an equation in this paper. Especially, General Emission Factor (GEF) was proposed to assess the relationship between CO 2 emissions and energy consumption. The results show that, higher GEF will result in more CO 2 emissions with the same energy consumption and in iron and steel making, the optimization of energy structure and development of eco-industrial park both have significant benefit on the carbon reduction.