By twice field survey on Dalangtan area in Qaidam Basin, many outcrops of mirabilite and carbonate clay interbeds were found in Xiaoliangshan. The well D26 section was selected for research in this study. Comparative salinology of saline sedimentary environment study confirmed that mirabilite is a cold saline mineral, and that carbonate clay and gypsum indicate relative warm and humid conditions. In this study, we applied XRD to mirabilite and carbonate clay interbeds, U-Th datings to gypsum, and carbon and oxygen isotopic analysis to carbonate clay. It is pointed out that, Dalangtan region has undergone five climate stages during penultimate glaciation (MIS 6): relative warm & wet stage(＞195.1 ka BP) — frigid and arid stage(195.1 ~ 169.9 ka BP) — relative warm & wet stage(about 169.9 ka BP) — frequently fluctuating stage(169.9 ka BP ~ 118 ka BP) — relative warm & wet stage(118 ka BP). Loess section and marine oxygen isotope studies show that, since middle and late Pleistocene，Dalangtan region not only was uplifted by activities of regional geology, but also response to globle climate change.