Abstract: This paper emphatically studies the.formation,composition and evolution regularity of clay minerals in strata of Momoge drill hole.According to the data of paleobiology and strata lithology,paleosedimentary environment and paleoclimate are restored,paleogeography is reconstructed in the Songnen Plain from the late Cretuceous,the Neogene,to the Pleistocene of the Quaternary. In the strata of the late Cretaceous,montmorillonite,as enclosed waterbody mineral,is dominant with good crystallinoty,reflecting the lakeshore sedimentary feature and hot and slightly wet paleoclimate at that time. In the Neogene,influenced by global warm and humid climate,the basin was in the.period when lakes and rivers alternately developed,corresponding forming 5 clay mineral association zones in which kaolinite or montmorillonite was alternately as main mineral.The climate underwent such change process from,hot and dry,hot and humid,warm and relatively dray warm and relatively 1 umid,to warm and slightly dry. In the Pleistocene of the Quaternary,iniluenced by global glacial climate, lakes,swamps and basnis in linland gradually shrank,at last became dry and cold steppes.In clay mineral association zones,illite was main minearal,adding into chlorite,Palecclimate underwent the provcss from cold and dry, warm and humid,warm and dry,to cold and dry.