The hydrochemical investigation and sampling were carried out in the Zuli River, one of the tributaries in the upperYellow River. This paper analyzed the spatial distribution characteristics and evolution process of the salty water in the Zuli RiverBasin. The results show that the TDS of the water body in the Zuli River Basin is generally high, and the water is salty. Thehydrochemical types of groundwater samples from the source area are dominated by the Mg-Ca-Na-HCO3. River samples are highlymineralized and dominated by the Na-Mg-Cl-SO4 type. The high salinity in the Zuli River Basin is characterized of the cationexchange and absorption, the groundwater discharge into the river after leaching salt stratum in the upstream, and eroding the soilsalts in both sides of the river. During the runoff process, the arid climate makes the water body further evaporating andconcentrating, which is the external hydrochemical evolutionary process of the TDS further increasing in the catchment. In short, themultiple sources of salinity, especially the high TDS groundwater discharge of the source area, the strong soil erosion and aridclimate in the basin, are the main reasons causing the loss of water resources function and the significant increase of TDS.