Abstract: This study is carried out to simplify the procedure of regionalization of groundwater hydrochemical type, and to objectively reflect spatial distribution characteristics of groundwater hydrochemical types. Based on the geographic information system (GIS) technology, the spatial analysis model for regionalization of groundwater hydrochemical type is designed and built by ArcGIS ModelBuilder. Using milligrams equivalent percent raster data of K⁺+Na⁺、Ca²⁺、Mg²⁺、HCO₃^-、SO₄^2- and Cl^-, the combinations and sequence of cations and anions are encoded, and the identification and spatial regiona-lization of groundwater hydrochemical type are automatically completed. The model is validated by measured sample data, and the results of the regionalization of groundwater hydrochemical types are compared with traditional methods. The result shows that the method is efficient and feasible by using spatial analysis model to identify and regionalize the groundwater hydrochemical type, and the overall effect of hydrochemical type regionalization is consistent with that of traditional methods, and the spatial analysis model can better reflect the spatial evolution characteristics of groundwater hydrochemical types.