The vascular plants in the Cheonbansan were listed 241 taxa; 72 families, 157 genera, 307 species, 27 varieties and 7 forms. Divided into 241 taxa; woody plants were 95 taxa (39.4%) and herbaceous plants were 146 taxa (60.6%). Based on the rare plants (IUCN) by the Korea Forest Service and Korea National Arboretum, 2 taxa (Viola albida, etc.). Based on the list of Korean endemic plants, 8 taxa (Salix koriyanagi, Lespedeza maximowiczii for. tomentella, Indigofera koreana, Weigela subsessilis, Carex okamotoi, Lilium amabile, etc.). Specific plant species by floral region were total 15 taxa (6.2% of all 241 taxa of vascular plants); Lonicera subhispida in class, Orostachys sikokianus, Ostericum melanotilingia in class, 9 taxa (Betula schmidtii, Quercus variabilis, Clematis patens, Spiraea blumei, Ilex macropoda, Vaccinium oldhami, Lonicera praeflorens, Microstegium japonicum, Hosta capitata) in class. The naturalized plants in the surveyed sites were 8 families, 13 genera, 16 taxa (Rumex acetocella, Silene armeria, Lepidium apetalum, Trifolium pratense, Oenothera odorata, Cuscuta pentagona, Xanthium strumarium, Eragrostis curvula, etc.) and naturalization rate was 6.6% of all 241 taxa of vascular plants. The vegetation of results in the Cheonbansan, a total of 4 plant communities; Pinus densiflora community, Quercus variabilis community, Quercus serrata community, Quercus mongolica community. The occupied in low-slope and valley of Quercus serrata community, mountain side of Pinus densiflora community, Quercus variabilis community, top and ridge of Quercus mongolica community.