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The Badain Jaran Desert, located in western Inner Mongolia, China, is characterized by an and climate and by occurrence of large dunes and permanent lakes within the dune field. The main objective of this paper is to describe landscape evolution and climatic change in this desert since the late Pleistocene. Special attention is given to the dune and lake deposits as well as to the water chemistry of the lakes. On the megadunes of the desert several calcareous cementation layers and cemented plant roots were observed, indicating a relatively moister climate during the last 31,000 years. The present hypersaline takes were filled with fresh or brackish water between 9 and 4 ka BP. On the basis of dune morphology and stratigraphy and lacustrine deposits, it is concluded that the enrichment of ions in the lakes and decline of their water surface result from aridification since the middle Holocene. The existence of more humid periods implies that the intensity of westerlies and Asian monsoons has changed perioldically in this desert since the late Pleistocene. (C) 2002 Elsevier Science Ltd and INQUA. All rights reserved.