Salt cores from the nonmarine Qaidam Basin, western China, are used to inter pret late Pleistocene/Holocene paleoclimate and brine evolution based on major ele ments and stable isotopes (hydrogen and oxygen) in fluid inclusions in halite. Layered primary halite with chevron and cumulate textures diagnostic of crystalli zation at the brine bottom and at the air-brine interface occurs to depths of 43 m (54 kyr B.P. based on U-series dating methods). Fluid inclusions in this halite contain the lake brines from which the halite crystallized. Variations in the major-element chemistry and activity of HzO in fluid inclusions with depth/time reflect changes in the ratio of inflow to evaporation and document relative basin aridity. Stable iso topes of hydrogen and oxygen in fluid inclusion waters are used to interpret paleo climate in terms of surface temperatures, although atmospheric circulation pat terns, sources of moisture, and other factors may also influence isotopic compositions. Relative C O j /^ in fluid inclusions from cumulate halite that contain trapped air preserve a record of atmospheric chemistry.Fluid inclusions in halite crystals 20 to 13 kyr B.P. in age have exceptionally low 8180 , 8D, and C 0 2, which coincides with the marine oxygen isotope record and the polar ice core record of global cooling during the last glacial period. At this time, halite precipitated from concentrated saline lake brines in the cool, but hyperarid, Qaidam Basin. Fluid inclusions in salt cores suggest that regional aridity may have limited glaciation on the Qinghai-Tibet Plateau during the last glacial, compared to North America and other areas.