Abstract: Based on detailed underground investigation, faults and layer slips on mid-and small-scale in coal seams of mined areas are studied. The results have shown that faults extended generally in NE direction. The most of them are layer faults, arraying isometrically. The layer slips are compound structures with NW-SE extending direction, which often occurred near the tops of coal seams No. 7, 8 and 10. The coal seams No. 7 and 8 were fractured severely, caused the thickness of coal seams No. 7 and 8 increase and decrease rapidly. The thinned coal seams are not only of directional characteristics, isometric characteristics, but also show superimposed compounds from different directions. The above stated characteristics of structures have a strong impact on coal production. Using known regularities, the structure characteristics in unmined area are forecasted, resulting notable economic benefits.