There are nine river terraces developed on the left bank of Yellow River around Yemingshan hill which is on the upside of Xiangshan-Tianjingshan fault. The highest terrace above the river is about 140m. At the same time, on the right bank of the river, there are only three terraces near Dawancun village (37027° 02"N, 104°58'38"E) , downside of the fault. The elevation of highest terrace is about 80m. The deposition of terraces on the right bank is obviously thicker than the ones on the left, and reach to 20m for the thickest one. Ages of the aeolian sand layers interbedded in upper part of the fluvial deposits in the Yellow River terraces in Shapotou area, Ningxia, were determined by Optically Stimulated Luminescence (OSL)dating method. 12 OSL samples were collected from the Yellow River terraces around Yemingshan hill and Dawancun village near Shapotou,and 3 samples were taken from the sand deposition section near Mengjiawan village (37°26' 10"N, 104°55'40"E) ,about 6kin away from the left bank of Yellow River. Most of the ages are younger than 74ka. This obvious discrepancy with the time of terraces formation suggested that the dated sand layers were not deposited at the same time when the terraces were formed, but in the cold and dry climate in the Last Glacial period. It indicates a pulse of the Tengger desert expansion cross the Yellow River during this time. This study provides firstly direct evidence that the sandy sediments of Tengger desert were expanded during the cold and dry climate of the Last Glaciation, in that time the aeolian sand activity was significantly strengthened.