Abstract: The aim of this study is to clarify the chemistry characteristics of karst groundwater in the eastern part of Gui'an new area of Guiyang, China. The correlation among water quality parameters and the spatial distribution of major ions were examined using SPSS, ArcGIS,MapGIS, and Origin based on the water chemistry test results of 50 groups of water samples and 68 sets of data in the study area. The groundwater chemistry characteristics of the study area were analyzed using the Shoka Lev's classification, Piper's plot, Gibbs plot, and ion ratio diagram. Results manifest that: 1) Ca²⁺ and HCO₃^- are dominant ions in the study area; Na⁺,SO₄^2-, F^-, and NO₃^- are of strong spatial variability, and TDS has a good correlation with each component.2) HCO₃-Ca,HCO₃-Ca·Mg,and HCO₃·SO₄-Ca are major groundwater types, of which HCO₃-Ca·Mg type accounts for 32.2%, the largest proportion. 3) The content of Mn, Fe, Al, and NH₄⁺ exceed groundwater quality standards and are mainly distributed in the Triassic Anshun Formation in the study area (T_1-2a), Daye Formation (T₁d) and other gypsum-salt-bearing formations, with Mn exceeding the standard by 8.47%. 4) Groundwater is in the rock-weathering control zone where the rock-salt-bearing formations are dominated by leaching and cation adsorption and the dissolution of Carbonate rock, which is the major source of Ca²⁺ and HCO₃^-, and the major reflection of water-rock interaction.

Key words: Karst groundwater, hydrochemical characteristics, excessive hydrochemical composition, genetic analysis, east part of Gui'an new area