Abstract: This paper deals with the water quality change during dewatering test in Xingtai Coal Mine. According to geochemical theory, the mine water is divided into two types of water quality which one is ordivician karst water and another is Daqing karst water, by using index composition, water quality map analysis method. Daqing karst water can be divided intothree types according to water quality too. The paper also calculates the proportion of Ordivician karst water in mixed one,therefore, points out the water rich areas in the mine and it's recharge source and quantity.