Abstract: In this paper, the lithological characteristics of large thick unconsolidated layers in vertical and lateral directions, in selected typical coal mines of Huainan, Huaibei, Datun, Yanzhou and Xingtai coalfields in Huanghuai area are analysed. Meanwhile, the influence of mining activities on ground water regime is also discussed from the aspects of water bodies, rock layers, and mining activities, etc. The study is of benefit to solution of some practical engineering problems.