【英文摘要】On the basis of field investigation, analysis of water and sediment samples taken from the Badain Jaran Desert, the Taklamakan Desert in western China, the project has been able to obtain new knowledge and/or new evidence regarding water cycle, chemical solutions in water bodies, sand characteristics and sand sources in desert environments. The outcome of this project is of significance for studying changes of desert landscapes and for understanding the interactions between various components in desert systems. By means of measuring ions and environmental isotopes in waters of lakes and in groundwater in southern Badain Jaran Desert, we examined the relationship between lake water and groundwater, suggesting that the groundwater of southern Badain Jaran Desert is mainly recharged by local rainfall. Based on the new water chemistry data from both surface and ground waters in southern Taklamakan Desert, we concluded that the ions in the river waters are mainly from rock weathering, whereas the ions in the groundwater are mainly from dissolving of evaporites. Low-level human imprints are recognized in the groundwater samples also. Through the measurements of geochemical trace elements, a comparison between various catchments in the Taklamakan has been made, showing that the coarse fractions of the aeolian sands are different from catchment to catchment but the fine fractions are highly homogeneous. It is for the first time that the oxygen isotopes of quartz grains from the sand seas and sandy lands of northern China are systematically examined. The results show that the oxygen isotopes of quartz grains are different between various deserts, confirmming the local origin of sand in each large desert system.