Abstract:In order to understand characteristics of hydrogen and oxygen isotopes in water environment and relationship between river water and groundwater in Lhasa River Basin, hydrogen and oxygen isotopes in Lhasa River water and groundwater were collected and analyzed in August 2019. The results show that the δD and δ18O values of Lhasa River water are -151.22‰ to -132.24‰ and -20.49‰ to -18.13‰ respectively, and the δD and δ18O values of groundwater vary from -147.69‰ to -120.86‰ and -19.56‰ to -16.08‰ respectively, both within the scope of global and China meteoric precipitation value. The groundwater heavy isotopes enrichment degree is stronger than the river water, the δD and δ18O values of river water and groundwater have the similar change characteristic, both have the certain hydraulic connection. Local meteoric precipitation is the main recharge source of water body in the basin. In addition to recharge of precipitation, groundwater also receives recharge from Lhasa River. There are obvious climatic characteristics of arid and semi-arid regions in the basin, and the precipitation water vapor is mainly affected by the Marine air mass in the bay of Bengal.