Abstract: By comparing the urban spatial expansion processes of Huainan and Huaibei since they were established, the paper analyzes their differences in evolution processes, characteristics and influence factors. The results show that: the form of the coal resource-based city usually is more dispersed. They usually follow the processes from relative compact to scattered and finally compact again, and share the characteristics of expending along the traffic lines. They generally experience four stages—enclave expansion stage, axial extension stage, inner filling stage and regional reconstruction stage. But they have differences in the urban scale, expansion speed and expansion intensity during different stages. However they are similar in the internal spatial structure changes, that three kinds of land-uses, including industrial district, residential area, commercial and public facilities land, expand more quickly than others. The internal space reconstruction began in 1980s and has become more seriously since then. The residential area's replacing industrial district, and commercial and public facilities land's replacing residential area are main forms of the internal space reconstruction. We think the resource endowment, mining area construction,topographic and geological conditions, transportation, technological progress, city function and city planning should affect the coal resource- based cities' spatial structure equally.