Abstract: In this study,the multi-year data of hydrochemistry,temperature and precipitation in the upper reaches of the Keriya River in 10 consecutive years from 2004 to 2013 and in some years before 1990 were collected.The multivariate correlation statistical method and hydrochemical diagrams were used to discuss the chemical composition and variation characteristics of main ions in water of the Keriya River as well as their affecting factors.The results are as follows:① The water salinity varied in a range of 203-1 081 mg·L^-1,and its mean value was 518 mg·L^-1.The salinity was higher than the average level of the rivers in the world;② Na⁺+K⁺ were the most abundant cations,and the cation concentration was in an order of (Na⁺+K⁺)> Ca²⁺> Mg²⁺.The main anion was dominated by HCO^-₃,and the anion concentration was in an order of HCO^-₃> SO²₄> Cl^-;③ The ion concentration was mainly affected by stream flow in summer,that is,the higher the flow was,the lower the salinity would be.The Keriya River was mainly supplied by surface runoff in raining season but almost by groundwater in dry season.The concentration of ions varied with the change of stream flow due to the different confluence paths in different periods;④ Weathering of rock was the main source of the ions in water of the Keriya River,especially that of evaporite.

Key words: hydrochemistry, ion concentration, annual change, interannual variation, principal component analysis, Keriya River, Xinjiang