Based on analyses of detrital minerals from the Quaternary sediments in the Salawusu River area, the authors discuss the change in climatic environment of that area since the last stage of the Middle Pleistocene. It is pointed out thai(1) during the development of loessial palaeosoil and the deposition of aeolian sand, the climatic environments were warm-humid and dry-cold respectively; (2)the fluviolacustrine facies of Salawusu formation and the aeolian sand of Chengchun Formation of the late Pleistocene are products of warm-humid and dry-cold climatic conditions respectively, in which the lake-swamp facies of Middle Chengchun Formation was formed under cool and humid climatic condition, and(3)during the deposition of the lake swamp facies of Dagouwan Formation and the fluviolacustrine facies,black soil and secondary loess of Dishaogouwan Formation(all belonging to Holccene period), the climate was relatively warm-humid,and during the deposition of medern Maowusu sandy desert,the climate turned dry-cold again.