Abstract: The 3^# coal seam in Xinjing Mine of Yangquan Mining Area is a strong outburst coal seam. To understand the development characteristics of nano-scale pore structure of 3^# coal, this study collected 3^# coal samples (XJ-3) at the heading of 3215 auxiliary air inlet lane in Fowa sub-area of mine field. The morphology and development characteristics of XJ-3 sample were observed by atomic force microscope (AFM), and the surface roughness R_a and root mean square roughness R_q of the coal were obtained by image analysis. The results show that the surface pore shape of 3^# coal in Xinjing Mine is mostly oval and pear-shaped, and the secondary is round, with a small amount of irregular strip shape. The connectivity between pores is general, and the throat is mostly cylindrical. The face rate of this coal is 5.74%, surface pores are mainly micropores and small pores, and mesopores and macropores are not well developed. The surface roughness R_a and root mean square roughness R_q values of the coal are 3.89 and 6.17 respectively. Compared with the coal with the same metamorphic grade, the surface of the coal has relatively weak concavity and convexity.