Abstract: The bottom gravel of Quaternary system in Huainan and Hualbei mine districts of Anhui Province has been studied for the upper limit of coal mining. There are many viewpoints about the genesis of the“bottom gravel”.In this paper，the authors studied the depositional characteristics，described the morphology and surface textures of the Quaternary bottom gravels in these districts. It is proved that the bottom gravels in these two districts are glacial till(glacial deposit)．Although these two mine districts are located about 200km away from each other, chemica1 simi1arity of limestone and dolostone gravels for these two districts indicates that these gravels share a common source．A “stagnation and deposition-falling stacking” model is proposed for genesis of these bottom gravels．