为探究新疆昌吉市平原区地下水化学特征及质量时空分布规律，采用数理统计、Piper三线图、Gibbs图、离子比值法、F值评分法和质量比对等方法对昌吉市平原区2016年42组及2011年9组地下水取样点检测数据进行分析。结果表明：昌吉市平原区潜水水化学类型主要有HCO3·SO4-Na·Ca型和HCO3·SO4-Na·Ca·Mg型，承压水水化学类型主要有HCO3-Na·Ca型和HCO3·SO4-Na·Ca型；研究区潜水水化学成分主要受蒸发浓缩和岩石风化共同作用的影响，承压水水化学成分主要受岩石风化作用的影响。通过2011年与2016年地下水原位点比对发现，潜水取样点中有3组质量不变、3组质量有所改善、2组质量劣化，承压水取样点1组无变化。影响地下水化学特征和质量时空分布的因素主要是自然因素和人为因素。

Changji City is the capital of Changji Hui Autonomous Prefecture, Xinjiang, and the increasingly serious quality problem of groundwater resources seriously restricts the local economic and social development. Based on the detection data of 42 groups of groundwater samples in Changji plain in 2016 (including 27 groups of unconfined groundwater samples and 15 groups of confined groundwater samples), the chemical characteristics of groundwater in this area are studied comprehensively by various means and its influencing factors are analyzed.At the same time, the detection data of nine groups of groundwater insitu samples in 2011 (including eight groups of unconfined groundwater samples and one group of confined groundwater sample) were used to reveal the law of spatial and temporal variation of groundwater quality in this area,in order to provide theoretical basis for the utilization and protection of groundwater resources. The mathematical statistics method is used to analyze the chemical composition content characteristics of groundwater Changji City,Piper diagram is used to analyze the chemical [JP2]types of groundwater, Gibbs figures are used to analyze[JP] the influencing factors of chemical characteristics of groundwater,ion ratio method is used to analyze the main sources of chemical composition of groundwater in the current year,F value evaluation method is used to evaluate the groundwater quality category,and quality comparison method is used to analyze the changes of groundwater quality insitu in 2011 and 2016. The [JP2]relationship between the average content of cations and anions [JP]in unconfined groundwater is Ca2+>Na+>Mg2+>K+ and HCO3->SO42->Cl-. The confined groundwater is Na+>Ca2+>Mg2+>K+ and Cl->HCO3->SO42-.The currentyear groundwater hydrochemical types were obtained by Piper diagram, with HCO3·SO4-Na·Ca and HCO3·SO4-Na·Ca·Mg types dominating in unconfined groundwater and HCO3Na·Ca and HCO3·SO4-Na·Ca types dominating in confined groundwater.The chemical characteristics of groundwater in current year were analyzed by Gibbs figures.The TDS range of unconfined groundwater and confined groundwater was mostly between 020 and 110 g/L. In unconfined groundwater, γ(Na+)/γ(Na++Ca2+) is more than 0.5 and γ(Cl-)/γ(Cl-+HCO3-) is less than 0.5. In confined groundwater,γ(Na+)/γ(Na++Ca2+) and γ(Cl-)/γ(Cl-+HCO3-) are mostly less than 0.5.The statistical results evaluated by Fvalue evaluation method show that the samples of groundwater quality in the current year of unconfined groundwater are 16 groups,6 groups,0 groups,3 groups,and 2 groups for Class Ⅰ,Class Ⅱ,Class Ⅲ,Class Ⅳ,and Class Ⅴ groundwater,respectively. The samples of groundwater quality in the current year of unconfined groundwater are 10 groups,2 groups,0 groups,2 groups,and 1 group. Compared with 9 groups of groundwater insitu points in 2011 and 2016,the quality category of samples C1,C22,and C40 in unconfined groundwater did not change,the quality category of samples C4,C34,and C39 improved from Class Ⅱ to Class Ⅰ,C41deteriorated from Class Ⅰ to Class Ⅱ,and C42deteriorated from Class Ⅰ to Class Ⅳ.The quality category of C2 in confined groundwater sample did not change. Both unconfined groundwater and confined groundwater in the plain area of Changji City are characterized by neutral to weakly alkaline,the highest Na+ overstandard rate and high TDS content.The spatial variation of Cl- and Ca2+ in unconfined groundwater is quite different,while the spatial variation of Cl- and Mg2+in confined groundwater is quite different.The hydrochemical types of unconfined groundwater are mainly HCO3·SO4-Na·Ca and HCO3·SO4Na·Ca·Mg, while the confined groundwater are mainly HCO3-Na·Ca and HCO3·SO4-Na·Ca. The chemical composition of unconfined groundwater in the study area is mainly affected by the combined effect of evaporation concentration and rock weathering,and the confined groundwater is mainly affected by the effect of rock weathering.The overall quality of groundwater in the study area was better in 2016,mainly Class Ⅰ.The samples of Class Ⅰ,Class Ⅱ,Class Ⅳ,and Class Ⅴ in unconfined groundwater accounted for 59.3%,22.2%,11.3%,and 7.4% of the total, respectively.While the samples of Class Ⅰ,Class Ⅱ,Class Ⅳ,and Class Ⅴ in confined groundwater accounted for 66.7%,13.3%,13.3%,and 6.7% of the total,respectively.Compared with the groundwater insitu samples in 2011 and 2016, it was found that the quality category of three groups of unconfined groundwater sampling sites remained unchanged,three groups improved,two groups deteriorated,and the quality category of one group of the confined groundwater sampling sites had no change.The main factors that affect the chemical characteristics and the spatial and temporal distribution of groundwater quality are natural factors and human factors.