Abstract: The detailed analysis of lithology, grain size and vertical distribution of the grain-size parameters are made for the samples collected from the sites DL-0 at the northern bank, DL-1 at the central part and DL-2 at the southern bank of the Dalai Nur Lake, Inner Mongolia. The peak values of sensitive grain size components are found to be quite different, indicating the spatio-temporal differences of provenances and sedimentary environments in the above-mentioned well sites. The sites DL-0 and DL-1 indicate stable sedimentary environments while the site DL-2 indicates variable sedimentary environments in which five depositional cycles are recognized. The clay, silt and sand ranging in grain size from 0 to 200 μm occur mostly at the depth of 1.5 m below the lake level of the Dalai Nur Lake. With the increase of the depths, the clay contents increase while the silt and sand contents decrease.