Abstract: In this study, the major ion concentrations of groundwater samples collected from four aquifers in the Renlou Coal Mine, has been analyzed by a series of statistical methods (correlation analysis, factor analysis and Unmix model analysis) for determining the hydro-chemical component controlling factors and the relationship and the qualitative and quantitative sources of major ions of aquifer system in coal mine. The results show that the major ion concentrations of water samples in different aquifer systems are different with each other, and the major hydro-chemical type is Na-Cl. Correlation analysis indicated that Ca²⁺, Mg²⁺ and SO₄^2- as well as Na⁺+ K⁺ and HCO₃^- had homologous relationship, and the relationship between the two groups in the aquifer system also existed. Factor analysis determined that the weathering of silicate minerals (source 1) and the dissolution of evaporated minerals (source 2) were two major sources controlling the chemical component of groundwater in the study area, and EPA Unmix model analysis revealed that the contribution rate of source 1 to coal bearing aquifer was >80%, the contribution rates of source 2 to Tertiary limestone aquifer and Ordovician limestone aquifer were >50% and >60%.