Characteristics of the soil salinity of the Manas River Valley in Xinjiang was studied using correlation analysis and principal component analysis methods, in combination with regional investigation of soil properties. Results show that the soils in this region are of the type of soils salinized mainly with sulfate, and of the grades of severely and moderately salinized soils. Profile distribution of soil salinity of the soils is characterized by bottom accumulation. Soil salt content (S_t) is in significant positive correlation with content of SO₄^2- and Ca²⁺. SO₄^2-is the dominant anion while Ca²⁺ the dominant cation of the salts distributed in all layers of the soil profile. SO₄^2-, Ca²⁺, Mg²⁺ and S_t are the eigenfactors to characterize soil salinization of the Manas River Valley. This study will provide an important theoretical basis for sustainable utilization of the soil resources in the Manas River valley of Xinjiang.