Abstract: The Hexi Corridor is located in the western part of the Gaansu Province, belonging typical interior arid region and characterized in the temperate desert climate. There are 326 species of seed plants, which belong to 52 families and 166 genera. The floristic characteristics in the area are as follows:1. Species are poorer, the seed flora in Hexi Corridor consists of 52 families, 166 genera and 326 species. The ratio of genus and species is 50.92%. Floristic dominance is obvious in this area, 5 dominant families contain more than 50 percent of genera and species in the flora;2. The Temperate Zone is superior to numbers of species in the area;3. On the life form of plants of the flora, it is primary perennial herbs and shrubs;the Hexi Corridor has obvious characteristics of Temperate Desert;4. The origin of flora in the Hexi Corridor is older;5.Quantitative comparison and analysis on florae in the Hexi Corridor and in related area such as Alashan, the Tarim Basin, the Zhungeer Basin and the Tsaidam Basin indicates that desert flora in Northwestern China is an unity according to their composition and evolution way.

Key words: the Hexi Corridor, flora, characteristics