Different typical water samples were collected from July 22 to July 28 in 2005 in Lijiang Basin of the Hengduan Mountainous Region for chemical characteristics study.Principal component analysis(PCA) and correlation analysis were used for data analysis,the results showed that the dominant cations were Ca²⁺ and Mg²⁺,whereas SO₄^-2 were major anions.The analytical results suggested that the orders of water concentration,from high to low,were the glacial lake water,melt water runoff,lake water,surface runoff and groundwater.PCA results showed the lithological characters definitively influenced the ion content of water in the Lijiang basin,which also were effected by human activities.Correlation analysis showed that the concentration of Na⁺,K⁺,Mg²⁺,Ca²⁺ highly correlated with the lithology,whereas Cl^-,and NO^-3 concentration had a positive correlation with human activities.High correlation between Ca²⁺ and Mg²⁺ suggested their strong common source.Further analysis shows that H₂SO₄ participating in and accelerating the carbonate and sulfate mineral dissolution related to the above.Cl^-and NO^-3 with strong correlation were closely related to human activities indicating Cl^-and NO^-3 have similar sources of which most come from human activities.