Abstract: Hydrogeochemical data were applied in analyzing the characteristics of karstic groundwater in coal mines in North China,distinguishing water outburst sources,examing the formation mechanism of groundwater in mining areas,and planning the protection of environment and water resources management.However,there are three "high" and one "disturbance",i.e.,high ground stress,high earth temperature,high karst water pressure,and mining disturbance in deep mining.Therefore hydrogeochemical environments change under the conditions of high pressures of rock and groundwater,high temperatures of rock and groundwater and long runoff of groundwater.Due to complicated conditions in deep mining,it is pointed out that chemical characteristics and recycle of deep groundwater and relationships between deep rocks and water yield property must be considered with theory and method of hydrochemistry.