To explore the water quality change and present status of lakes in the Tibet Plateau,water samples was collected from 33 lakes (22 tectonic lakes and 11 glacial lakes) along the highways of G315,S301,S302,S206,G219 and G318 and in the Yairu Zangbo Basin from September to October 2016. These samples were analyzed for ion concentration,chemical composition and salinity,and then the results were compared with previous studies before the 1990s to reveal the water quality change and its driving factors. The results show that: ① the concentration and chemical composition of water for these lakes in the Tibet Plateau are significantly different. The concentration of chemical ions of water samples in the tectonic lake is much higher than that in the glacial lake. According to the ionic strength,the 22 tectonic lakes are devided into 6 freshwater lakes,4 micro-saltwater lakes,1 salt water lake and 11 salt lakes,respectively,the 11 glacial lakes all belong to freshwater lake. According to the chemical composition of the lake,the 22 tectonic lakes contain 6 Ca~(2+)(Mg~(2+)) -SO_4~(2-) lakes and 16 Na~+(K+) -Cl~- lakes,and the 11 glacial lakes are all Ca~(2+)(Mg~(2+)) -SO_4~(2-) lakes. ② The salinity of lake water significantly varies depending on the sampling locations and periods,and the high latitude usually shows higher lake salinity. Compared with that in the 1990s,mineral concentration of some lakes collected in this study are less,and the desalination trend may be associated with climate warming,the increasing precipitation and glacial melt as well as decreasing evaporation in the Tibet Plateau. ③ Due to the geographical environment,climate background and water chemical characteristics,the values of pH and total dissolved solids of most tectonic lakes in the Tibet Plateau were seriously beyond the national standards of surface water quality,and six tectonic lakes are polluted by F~-. The glacial lake is polluted by Fe,Mn,Cr and Ni,especially heavy metal elements Cr and Ni are extremely serious,which may be related to human activities.