The vascular plants of the studied area in the Mt. Bangjang was listed 422 taxa : 106 families, 299 genera, 372 species, 1 subspecies, 46 varieties and 3 forms. Based on the list of the rare plants by the Forest Research Institute, 5 taxa were recorded in the studied areas; Lilium distichum(Preservation priority order : No. 159), Tricyrtis dilatata (No. 97), Aristolochia contorta (No. 151), Prunus yedoensis (No. 110), Patrinia saniculaefolia (No. 122) and based on the list of Korean endemic plants, 9 taxa were recorded; Cephalotaxus koreana, Carex okamotoi, Populus tomentiglandulosa, Salix purpurea var. japonica, Prunus yedoensis, Forsythia koreana, Paulownia coreana, Weigela subsessilis, Patrinia saniculaefolia. Specific plant species by floral region were total 29 taxa; Prunus yedoensis in class V, 3 taxa(Acer palmatum, Asperula lasiantha, Lonicera subhispida ) in class III, 5 taxa(Lilium distichum, Potentilla dickinsii, Caryopteris incana, Patrinia saniculaefolia, Ligularia fischeri) in class II, 20 taxa(Ulmus parvifolia, Clematis patens, Aconitum jaluense, Ilex macropoda, Grewia biloba var. parviflora etc.) in class I. The naturalized plants in this site were 13 families, 31 genera, 36 species, 2 varieties, 38 taxa and naturalization rate was 9.0% of all 422 taxa vascular plants. Because of recent rapid increase of cars and people around here, analysis shows many naturalized plants and high naturalized ratio. And wild plants disturbing ecosystem like Ambrosia artemisiifolia var. elatior have been increasing. So, it needs continuing control and conservation measures on the plant ecosystem.