This research was carried out in Sivas province between 2001 and 2003 years and 1450 plant specimens were collected during this period. Identification of the specimens revealed presence of 340 taxa belonging to 164 genera in 45 families. All of the 340 taxa belong to Spermatophyta division. Of these one taxon belongs to Coniferophyta, the remaining 339 taxa belong to Magnoliophyta subdivision. Some 43 taxa of Magnoliophyta are classified within the Liliopsida and remaining 295 taxa within the Magnoliopsida. A total of 122 taxa determined in the research area (35.8%) are endemic for Turkey. Eight taxa are new records for square B6. The scattering ratios of the taxa for the phytogeographic regions are as follows: Irano-Turanian elements 173 (50.2%), Euro-Siberian elements 9 (2.8%), Mediterranean elements 14 (4.3%), Widespread and unknown scatteries 144 (42.7%). The largest 10 families according to taxon numbers are as follows: Asteraceae 61, Fabaceae 39, Lamiaceae 38, Liliaceae 25, Brassicaceae 24, Caryophyllaceae 21, Apiaceae 16, Boraginaceae 16, Poaceae 10, and Scrophulariaceae 10. The largest ten genera and number of species included are as follows: Astragalus L. 17, Salvia L. 13, Centaurea L. 13, Achillea L. 8, Silene L. 7, Gypsophila L. 7, Onobrychis Adans. 6, Onosma L. 6, Allium L. 6, Helichrysum Gaertner 5, Iris L. 5. (C) 2004 Elsevier Ltd. All rights reserved.