为研究和田河中下游流域地下水水化学特征及其演化规律，采用Piper三线图、Gibbs图、PHREEQC软件和数理统计等方法对该地区水化学特征、主要溶质组分来源和演化规律开展了综合研究分析。结果表明：（1） 地下水中八大常规离子含量整体偏高，尤其是Cl^-、SO₄^2-、Na⁺、Ca²⁺和HCO₃^-占比较大。（2） 水化学溶解组分空间差异性明显，除少部分地区水化学类型表现为SO₄·Cl-Ca·Mg型外，大部分均以SO₄·Cl-Na型为主。地下水呈弱碱性，大部分地区水样点水质基本满足生活饮用水标准。部分绿洲平原区受人类生产活动影响，水中NO₃^-含量明显异常。（3） 在水-岩作用和阳离子交换作用下，地下水中Na⁺、Ca²⁺、Mg²⁺、Cl^-、SO₄^2-等离子组分主要物质来源于岩盐、方解石、白云石和石膏等矿物的溶解。在向下游细土平原和沙漠区径流过程中，受蒸发浓缩作用普遍控制影响，水中各离子浓度含量不断增大。（4） 在开放性较好的系统环境中，CO₂促进了各矿物的溶解，使得地下水中各离子含量不断溶解聚集，浓度增大。进入下游冲积平原区后，受细粒砂土介质层阻隔影响，地下水径流与交替强度减弱导致溶滤作用变差，蒸发浓缩作用逐渐占主导地位，进一步加大了水中离子含量和水化学类型的差异性。研究结果可为和田河流域水资源合理开发利用和生态环境保护提供理论依据。

To investigate the chemical characteristics of groundwater and its evolutionary patterns in the middle and lower reaches of the Hotan River Basin, Xinjiang, China, this study analyzed 21 groundwater samples from the area. It included an examination of the constituents and origins of groundwater solutes and the reverse simulation of hydrogeochemical processes. The analysis employed Piper trilinear diagrams, Gibbs diagrams, PHREEQC software, and mathematical statistics to explore the chemical properties of groundwater, the principal sources of solutes, and their evolution in the study region. The results revealed that: (1) High concentrations of eight conventional ions in the groundwater, with Cl^-, SO₄^2-, Na⁺, Ca²⁺, and HCO₃^- being particularly abundant. (2) There was a significant spatial variability in the dissolved constituents of the groundwater. The predominant chemical types were SO₄·Cl-Ca·Mg and SO₄·Cl-Na, with the latter being more common across most areas. The groundwater’s alkalinity was generally low, and the water quality in most regions met daily drinking water standards. However, in some oasis plains, elevated NO₃^- levels were attributed to human activities. (3) The dissolution of minerals such as halite, calcite, dolomite, and gypsum, facilitated by water-rock interactions and cation exchange, was identified as the main source of Na⁺, Ca²⁺, Mg²⁺, Cl^-, and SO₄^2- ions in the groundwater. During transit to finer soil plains and desert areas, ion concentrations increased due to evaporation and concentration processes. (4) In open system conditions, CO₂ enhanced the dissolution of various minerals, leading to increased ion concentrations. As groundwater flowed into the alluvial plains downstream, the fine sand layer acted as a barrier, reducing the intensity of groundwater flow and solute leaching, with evaporation and concentration processes becoming more dominant. This study provides a theoretical foundation for the sustainable development and management of water resources and environmental protection in the Hotan River Basin.