Abstract:Through geophysical, hydrogeological investigation, drilling and pumping tests, combining with regional hydrological, meteorological, geological and hydrogeological and other information, hydrogeological parameters of fracture-karst water in the upper part of the cover have been obtained, and karst water amount has been calculated as well. By using "big well method", the mine water inflow has been predicated, and basic hydrogeological characteristics of eastern mining area have been identified. It is said that under natural conditions, discharge of fractured karst water to basic rock fissure water is weak; when hydrodynamic conditions changed, fractural karst water could easily lead into the tunnel collapse, and will produce a greater threat to the exploitation of the lower part of the ore body .