Abstract: The physical and chemical properties of four kinds of BOF dust and their effects on the combustion performance of pulverized coal were studied by using a variety of detection methods. The results show that there are Fe₃O₄,Fe₂O₃,CaO and CaCO₃ in the phase composition,and the microstructures of the samples are obviously different.The pores with size below 10 nm contribute to the main surface area,while the pores above 10 nm contribute to the main pore volume.The pulverized coal combustion reactivity has been improved by reducing the ignition,burnout and corresponding temperature of reaction peak due to dust addition,,nervetheless too high carbonate content will inhibit its enhanced combustion effect.