Abstract: Groundwater is an important water resource for water supply, and the hydrochemistry is one of the key factors determining its availability. In this study, the southern near-suburb plain of Beijing was taken as an example, multiple approaches including hydrogeochemical diagrams, multiple statistics analysis and spatial interpolation model were performed, to reveal groundwater chemistry and its genesis in arid and semiarid regions undergone rapid urbanization and densely agricultural practices. The results demonstrated that groundwater was generally slightly alkaline fresh water in the study area. The hydrochemical type of groundwater were dominantly HCO₃-Ca and Cl-Mg·Ca type, along with a few of HCO₃-Na·Ca type. Elevation of NO₃^- concentrations were observed in both shallow and deep aquifers. The hydrogeochemical faces evolution of shallow and deep groundwater was significantly related to the elevated NO₃^- concentrations. The dominant anions evolved gradually from HCO₃^- to SO₄^2- and Cl^- with the increase of NO₃^- concentration. Hydrogeochemical components of shallow and deep groundwater were controlled by both natural and anthropogenic factors. The spatial distribution of dominant controlling factors of groundwater chemistry was governed by the aquifer structures. The hydrochemical compositions of groundwater in the northwestern urban areas with single aquifer structure were dominantly controlled by anthropogenic factors, while that in the southeastern agricultural areas with multiple aquifer structure were mainly governed by natural factors. The natural factors controlling groundwater chemistry included rock weathering, minerals dissolution and ions exchange. Ground surface pollutants input was the main anthropogenic factor controlling groundwater chemistry. While the reclaimed water used for agricultural irrigation was found to have little impact on groundwater chemical evolution.