Western forests in Iran cover more than 5 million hectares which compromised 45% of total forest of Iran. Floristic composition of this forest is poorly described while they are under sever threat of degradation. Species compositions were studied through 797 ha of Perdanan pastures in 30 km far from Piranshahr. The average rainfall is 670 mm per year, the altitude is 1455 m and the climate is semi-arid and cold. In total 108 species belong to 29 family within 84 genes were identified. The most spacious family were Poaceae (16 species, 18.39%) followed by Asteraceae (15 species, 13.9%), Fabaceae (14 species, 12.96%) and Apiaceae (8 species, 7.4%). Therophytes were the dominant life forms, accounted for 33.3%, followed by hemicryptophytes (28%), phanerophytes (21.3%), chamaeophytes (10.2%) and cryptophytes (6.4%). Irano-Turanian was the most dominant 34.5% (30 species) chorotypes and 28.17% (25 species) belong to Irano-Turanian-Mediterranean-Euro-Siberian in which showed this area not only located in Irano-Turanian but is on the belt between these two areas.
