This study was carried out to investigate the distribution status and urbanization index of the naturalized plants. For this purpose, 7 cities and counties in the eastern area of Jeollanamdo were selected and investigations were conducted on a total of 14 sites, during the period of March 2006 to November 2008. The naturalized plants were identified as 123; 22 families, 75 genera, 118 species, and 5 varieties. As for the urbanization index, Suncheon city had the highest level of urbanization (33.45%) and Gurye county the lowest level of urbanization (20.21%). Classification families were as follows: Compositae 40 kinds (30.1%) Gramineae 17 kinds (12.8%) and Leguminosae 14 kinds (10.5%). Major communities of naturalized plants consisted of 20 communities including Erigeron annuus community, Erigeron canadensis community, Alnus firma community, Amorpha fruticosa community, Oenothera odorata community, Bidens frondosa community, Coreopsis tinctoria community, Ambrosia artemisiifolia var. elatior community etc. Invasive naturalized plants consisted of 5 taxa: Ambrosia artemisiifolia var. elatior, Ambrosia trifida, Eupatorium rugosum, Paspalum distichum var. indutum and Paspalum distichum. The distributional characteristics of naturalized plants were divided on the basis of six areas associated with ecological characteristics of a habitat.