Feldspathic sandstone region is one of the main concentrated sources of coarse sediment in the middle reach of Yellow River. Studying the relationship between environmental factors and soil organic matter (SOM) has great significance to guide vegetation construction and reduce coarse sediment in Yellow River. We collected soil samples at 0-20, 20-40 and 40-60 cm depths in 150 sampling sites in Baojiagou Watershed of Feldspathic sandstone region in Jungar Qi of Inner Mongalia, measured SOM of the samples and analyzed its relationship with environmental factors through path analysis and redundancy analysis. The results showed that SOM content followed the order of arbor > shrub > grassland > farmland > bare land in different land use types, and the order of valley floor > slope > ridge in different topography. Redundancy analysis (RDA) demonstrated that TWI (topographic wetness index, X₁), land use type (X₃), slope position (X₂) and soil thickness (X₄) could strongly explained the spatial variation of SOM. Path analysis showed that the relation between SOM and environmental factors could be presented by Y=1.054+0.099X₁+2.722X₂+0.766X₃-0.001X₄ . In conclusion, slope position and land use type were the dominant factors affecting the spatial variation of SOM, soil thickness was closely related to the vertical spatial variation of SOM in feldspathic sandstone region.