Abstract: Clay mineral composition in fluviolacustrine deposits or the Heilu soil in the Sjara-Osso-Gol Group of the lower Mid-late Pleistocene in the Dishao-gouwan profile of Sjara-Osso-Gol River, the Middle and Lower Holocene are dominated by illite, yet it is accompanied with a little quantity of mineral such as Kaoline; and the caly mineral composition, which are dominated by aeolian sands are mainly illite-chlorite, accompanied with a little montorillonite in the Upper and the Lower Chengchuan Group of the Upper Holocene. The clay mineral composition in the Quaternary strata of Reijiagouzuizi, Madaqu and the Northwestern marginal land of Sjara-Osso-Gol River area fundamentally coincide to thp.se in Dishaogouwan profile of Sjara-Osso-Gol River. This shows that the Quaternary aeolian sand and loess in the study area deposited under a relative dry and. cold climate condition, but the fluviolacus strine facies or limnetic facies and paleosoil formed under the relative warm wet climatic condition. Therefore, the Late Pleistocene Malan loess or aeolian sands can be a comparison with the fluviolacustrine-deposits under Malan loess and aeolian sands of Chengchuan Group and Sjara-Osso Gol Group. The clay mineral composition in the Quaternary strata in this area re-flects that since the Late Pleistocene, the climate had undergone several replacement from warm to cold, to temperate wet, dry cold, warm wet and dry cold, which were roughly identified with the trends of climate changes in the Northern Hemisphere, i.e Yumu-Lisi Interglacial Staircase, Main Yumu Glacial Period and the warm period after glacial period.