The vascular plants of the studied area in Nonsan economical forest growing site appeared to be 341 taxa; 81 families, 218 genera, 290 species, 1 subspecies, 42 varieties and 9 forms. Based on the list of Korean endemic plants, 5 taxa existed; Cephalotaxus koreana, Thalictrum actaefolium, Asperula lasiantha, Populus tomentiglandulosa (Planted species), Paulownia coreana (Planted species). Specific plant species by floral region were total 13 taxa; Cirsium setidens in class III, Potentilla dickinsii in class II, Cephalotaxus koreana, Pinus koraiensis (Planted species), Hosta capitata, Juglans mandshurica, Alnus hirsuta, Quercus variabilis, Ulmus parvifolia, Dictamnus dasycarpus, Gwenia biloba var. parviflora, Vaccinium oldhami, Trigonotis icumae in class I. The naturalized plants in this site were 9 families, 19 genera, 20 species, 1 varieties, 21 taxa and naturalization rate was 6.1% of all 341 taxa vascular plants. The communities were classified into Quercus acutissima community, Pinus densiflora community, Quercus variabilis community, Platycarya strobilacea community, Quercus aliena community of natural forests and Pinus rigida community, Metasequoia glyptostroboides community, Larix leptolepis community of artificial forests.