Abstract: The study shows that there are 271 endemic plant species in 119 genera of 38 families in Xinjiang. Under effects of the peculiar landforms of “two basins between three mountains” and the climatic conditions, the endemic plant species are more in the mountains where precipitation is high than those in plains and deserts. The endemic plant species are mainly distributed in the valley in the Tianshan Mountains, Altay Mountains, Kunlun Mountains and Pamirs. The endemic plant species are less in the Tarim Basin and TurpanHami Basin in south Xinjiang due to the severe natural environment; climatic conditions and the flora origin in the Junggar Basin are peculiar in arid northwest China, there are 118 endemic plant species, and they occupy 43.54% of the total in Xinjiang. Geographic distribution of endemic plant species in Xinjiang is analyzed, the formation causes are researched, and it is put forward that the conservation of endemic plant species is important for maintaining the biodiversity in Xinjiang. The results can be referred in further study on floras in Xinjiang.  

Key words: endemic plant species, distribution, biodiversity, Xinjiang