Abstract: On the basis of analysing the groundwater regime characteristics in the researched region,the saturation index of carbonater mineral in each bore-hole's karst water was calculated by using chemical thermodynamics method. After re- searches on the relation between the saturation indexes of minerals in water and the groundwater regime types,the distribu- tion laws of rich water were discovered. The exploration showed that in karst region,the water resource site should be selected in shallowly buried limestone zones where the groundwater regime varies less,the retardation time of water is short and the saturation index of carbonate mineral in water β_c is more than one and β_d less than one.