Present paper deals with the comparative study of three soils which are derived from loessal material,tuff and granite respectively on the hills in the northwest of Beijing.The results obtained are as follows:1.Under semi-arid continental climatic conditions,the soils are mote or less developed and characterized by such features es lack of watetr soluble salts in the soil due to leaching,apparent movement of carbonates in soils,more clays in subsoil due to physical weathering in situ,base saturated,Neutral to slightly alkaline in reaction,comparatively uniform SiO₂/Al₂O₃ ratios throught profile,and hydromica and montmorillonite as the main clay minerals in soils.