中文摘要：

星子河流域处于中国西南岩溶区的东南边缘,该流域岩溶水化学特征明显.利用因子分析方法对其水化学特征进行详细分析,结果表明该流域水化学组分以Ca2＋和HCO3-占绝对优势;其次是Mg2＋和SO42-,其余的Na＋、NH4＋、K＋、F-、Cl-、NO3-等组分含量很少.星子河流域水化学类型是典型的的重碳酸-钙（镁）型,碳酸盐岩、白云岩的风化和水岩相互作用为其水化学做出了主要贡献,自然因素是控制其水化学的主导因素;人类活动对该流域水化学也产生了一定影响,水质状况较好.

英文摘要：

The Xingzi River basin in the northern Guangdong province belongs to the part of the southwest karst area of China, but in the southeast edge of it. Its karst water chemical characteristics appears significantly. Factor analysis is used to analyze all of the hydrochemical data,and the results show that the water chemical composition are Ca2＋ and HCO~ which accounted for an absolute advantage in this basin. The following component is Mgz＋ and SO~-, and the rest of the component is Na＋, Nil,＋, K＋, F-, CI-, NO~- and so on, but its proportion is very low. The hydroehemical type of the Xingzi River is typical bicarbonate-calcium （magnesium） （HCO3^--Ca^2＋ （Mg^2＋））. The weathering of carbonate rocks and dolomites and the water-rock interaction makes a major contribution to the water chemistry, and the natural factor is the dominant factor controlling water chemistry. Human activities also had a certain impact on its water chemistry in the watershed. The water quality of the basin correspond the national drinking water safety standards, and its water quality is very good.