Lop Nur is a typical inland dry salt lake in the eastern end of the Tarim Basin within the interior of Eurasian continent.Thick evaporite was developed in the northern depression since the middle Pleistocene, and this was active response to global cooling and uplift of the Qinghai-Tibet plateau.In this study, carbonate content,carbon and oxygen isotopic compositions were analyzed for 203samples of evaporite series from the first deep core (LDK01)in the Luobei depression to reveal evolution features of paleoenviroment in Lop Nur since the middle Pleistocene.The research indicates that:(1)delta~(18) O anddelta~(13) C values show an obvious synchronous increasing trend,and the evaporation and precipitation ratio has the most significant influence overdelta~(18) O of water in the lakes,especially in the arid region;(2)Periodic fluctuation ofdelta~(18) O anddelta~(13)C indicates an environment of alternating wet and dry paleo-environment and the variations of the runoff into Luobei depression;(3)Rapid aridification of Lop Nur should not be driven solely by global climate change,and be the joint result of cooling of global climate and uplift of the Tibetan Plateau.