Arasbaran protected area is located in NW Iran, is one of nine designated Biosphere Reserves in Iran. According to the literatures and the current study, 1067 plant taxa are identified in the area. Eighteen plant taxa of the area are endemic to Iran. Hemicryptophytes (42.5 %) are the most frequent life forms in the reserve followed by therophytes (25.8 %), cryptophytes (18.8 %), phanerophytes (8.1 %) and chamaephytes (4.8 %). Remarkable number of Irano-Turanian and Euro-Sibirian species characterizes the phytogeography of the area. Due to transitional climate of this area, two or pluriregional elements are frequent.