Abstract:In order to analyze the groundwater chemical characteristics and the groundwater quality in the surrounding area of Dongping Lake, using methods such as ion analysis, statistics method, piper trilinear diagram and Gibbs diagram, the spatial and temporal distribution of Total Dissolved Solid(TDS), ion characteristics, hydrochemistry type, influencing factor and ion source during dry and wet periods in the area studies were analyzed. Using comprehensive evaluation method, the groundwater quality was evaluated, and its spatial and temporal distribution and the causes of water quality were analyzed. The results show that the TDS value of groundwater in the surrounding areas of Dongping Lake is generally high, and there is slight difference in the spatial distribution of dry and wet periods; groundwater cations are mainly Ca2+ and Na+, anions are mainly HCO3- and SO42-, and the main hydrochemical type is HCO3?SO4-Ca?Na type water of dry season, and HCO3-Ca?Na type water is the main type of wet period. The chemical characteristics of groundwater of dry season are mainly affected by the rock weathering and partly by the evaporating concentration, and the main source of ions is the combined action of evaporite dissolution and carbonate dissolution. The wet period is mainly affected by rock weathering, and the main source of ions is carbonate dissolution; the groundwater quality in the area studies is relatively poor, and the water samples in the dry period and the wet period are Grade IV (Poor) and Category V (very poor) water accounted for more than 50%, but the distribution area of category II (good) water and III (good) water in high water period is wider than that of similar water in low water period.