The vascular plants in the Mt. Manduk was listed 560 taxa composed of 110 families, 345 genera, 488 species, 1 subspecies, 67 varieties and 4 forms. Based on the list of the rare plants by the Forest Research Institute, 4 taxa were recorded in the studied areas; Lilium distichum (Preservation priority order; No. 159), Tricyrtis dilatata (No. 97), Aristolochia contorta (No. 151) and Prunus yedoensis (No. 110). Based on the list of Korean endemic plants, 12 taxa were recorded; Cephalotaxus koreana, Carex okamotoi, Lilium amabile, Populus tomentiglandulosa, Salix purpurea var. japonica, Pseudostellaria multiflora, Prunus yedoensis, Stewartia koreana, Forsythia koreana, Paulownia core ana, Weigela subsessilis and Aster koraiensis. Based on the list of approved for delivering overseas of plants, 7 taxa were recorded; Carex okamotoi, Lilium distichum, Aristolochia contorta, Vaccinium oldhami, Paulownia coreana, Asperula lasiantha and Saussurea seoulensis. Specific plants by floral region were total 32 taxa; Prunus yedoensis in class V, Wistaria floribunda in class IV, 5 taxa (Girardinia cuspidata, Spiraea salicifolia, Acer palmatum, Stewartia koreana, Asperula lasiantha) in class III, 3 taxa (Potentilla dickinsii, Viola tokubuchiana var. takedana and Caryopteris incana) in class II and 22 taxa (Pinus koraiensis, Hosta capitata, Chloranthus japonicus, Salix glandulosa, Juglans mandshurica, etc.) in class I. The naturalized plants in the surveyed sites were 14 families, 36 genera, 44 species, 2 varieties, 46 taxa and naturalization rate was 8.2% of all 560 taxa of vascular plants. Wild plants disturbing ecosystem like Ambrosia artemisiifolia var. elatior have been increasing. Therefore, continuous control and conservation measures are needed on the ecosystem of Mt. Manduk.