The Xarxili Nature Reserve (45°07'43″-45°23'15″N,81°43'09″-82°33'18″E) is located in the southern piedmont of the Alataw Mountain in Xinjiang,its western part borders on the Republic of Kazakhstan,and its area is 314 km2. Since the ancient times,this area has been the territory of China. It was forcibly occupied by the former Soviet Union before the 1960s,and it was a disputed area between China and the former Soviet Union due to a series of unfair treaties imposed by tsarist Russia. After the disintegration of the former Soviet Union,the area became as a disputed area between China and the Republic of Kazakhstan. A series of agreements and joint communiques were signed after carrying out the equal and friendly consultations between the two countries in the 1990s,and then the new national boundaries and boundary lines in the disputed area were delimited. As a result,the Xarxili Nature Reserve returned to China in 1999. After carrying out on-the-spot investigations,it has been found that there are 1 680 species of vascular plants (including the subspecies and variants) in 517 genera and 81 families,among which there are 23 species in 14 genera and 9 families of fern,9 species in 3 genera and 3 families of gymnosperm,and 1 648 species in 500 genera and 69 families of angiosperm. Analysis of distribution patterns of the genera and species reveals that the proportions of the north-temperate-zone distribution pattern and its variants,temperate distribution pattern of the Old World and its variants are the highest because of the geographical location and the temperate features of the flora in this area. The proportions of the Mediterranean and West Asian-Central Asian distribution patterns and their variants are the second highest,and the proportions of the temperate Asian and tropical distribution patterns are the third highest. The proportions of East-Asian distribution pattern and its variants and the North-American discontinuous distribution pattern are the lowest. These reveal that there are the most interflows between the flora in this area and that in the Old World temperate zone,Mediterranean and Western Asia-Central Asia,there are also certain interflows with the temperate Asian and tropical flora,and the interflows with the East Asian and North American flora are the lowest.