Abstract: The Zada Xiangquan River valley in the western part of Ngari prefecture is one of the main distribution areas of the mountainous desert on the Qinghai-Tibet Plateau, but there is a lack of data on desert vegetation in this area. In order to find out the background of desert vegetation in this area, this study was based on the field survey of 42 desert sample plots in Zada County, Nagri, Tibet from 2018~2023, and the classification and community characteristics of desert vegetation in the basin were analyzed. The results showed that there were 8 desert alliances in Zada County, Tibet, including 2 temperate shrub deserts: Caragana versicolor desert and Ephedra intermedia desert, and 6 temperate semi-shrub and herbaceous deserts, Ajania fruticulosa desert, Ephedra gerardiana desert, Krascheninnikovia ceratoides desert, Krascheninnikovia eversmanniana desert, Lactuca orientalis desert and Seriphidium thomsonianum desert, Notably, 5 desert alliances (C. versicolor, E. gerardiana, K. eversmanniana, L. orientalis, and S. thomsonianum deserts) are newly recorded desert types.. A total of 82 species of vascular plants belonging to 51 genera belonging to 20 families were recorded, Among them, the life forms are mainly hemicryptophytes and perennial forbs . The ecological type for water were mostly hyperxerophytic and typical xerophytes, including most of the building and associated species of desert vegetation, such as Ajania fruticulosa, Ephedra intermedia, Krascheninnikovia ceratoides, Lactuca orientalis, Krascheninnikovia eversmanniana, etc. The Central Asian-Asian component is the most important component of the geographical floristic type, followed by the Tibetan Plateau and the Eastern Paleoarctic. The results of this study provide basic data and information for understanding the status and distribution characteristics of desert vegetation resources in this region, clarifying the types and characteristics of desert vegetation in the Qinghai-Tibet Plateau, and regional biodiversity conservation.

Key words: Zada County, desert, Ecological type for water, vegetation type, community characteristics