Field investigations and laboratory analyses show that there existed long-lasting and extensive palaolakes between 18,000 and 42,000 yr B.P. in the Tengger Desert, NW China. This palaolake phase developed in a mild humid-warm climate that was very different from that of present. Geochemical data, palynological evidence and grain size variations demonstrate that the lake levels had fluctuated greatly with the climate changes and these fluctuations can be correlated with the Dansgaard-Oeschger and Heinrich events. ¿ 2001 American Geophysical Union