Kavir Biosphere Reserve covers an area of 686598 hectares situated in the northwest of Dasht-e-Kavir and east of Daryach-e-Namak. The Biosphere Reserve presents a variety of habitats, including cliffs and rocky outcrops, piedmont plains, gravelly, deserts and sand dunes, saline plains and salt marshes, and seasonal rivers and springs. The main aim of this research is to identify the plant species and to introduce of the flora in Kavir biosphere reserve. For this purpose, plant samples were collected from different habitats of the area in three growing seasons between 1994-1999. The life forms of species were determined and the biological spectrum of the area was plotted. The position of the area concerning phytogeographical classification was studied based on geographical data and references. A total number of 359 species and subspecific taxa was identified. These include 3 gymnosperms, 312 dicotyledones and 44 monocotyledones. Altogether, 43 families and 224 genera are known from the area. The following families have the highest number of species: Chenopodiaceae, Asteraceae, Brassicaceae, Poaceae, Boraginaceae, and Fabaceae. Therophytes with 198 species (55.1%) are the most frequent life forms in the area. The distribution of 245 species (68.3%) is restricted to Irano-Turanian region. Of these, 30 species (12.2 %) are endemics of Iran. . | 
