The vascular plants observed in the area were composed of a total of 184 taxa; 74 families, 141 genus, 168 species, 10 varieties, 4 breeds and 2 sub-species. The only rare or endangered species found in the area was Phelloterus Littoralis Bentham. The four endemic plants were found growing in the area like Athyrium koryoense, Carex kobomugi Ohwi, Lespedeza maximowiczii var. elongata NAKAI and Weigela subsessilis L.H. Bailey. Specialized plants of Yeondo were a total of 48 species; 36 taxa in Grade I, 2 taxa in Grade II and 10 taxa in Grade III. There was no species in Grade IV and V. The attach of naturalized plants is slow because the island has fewer number of tourists and visitors than other islands. Temperate evergreen plants grow on rocky areas and cliffs on Yeondo, so constant monitoring is needed. The measures should be taken to protect the plants from the development. As abandoned paddy fields or fallow fields become swampy, there are a variety of aquatic plants growing. In the respect, a conservation measure are needed.