This study was carried out to investigate the temporal variation of vascular flora in island of Song-i-do. The vascular plants were surveyed 1989 and 2010-2011, respectively. The surveyed results were summarized as 337 taxa, 87 families, 227 genus, 291 species, 2 subspecies, 37 varieties and 7 forms. This results contain more than 215 taxa, 68 families, 157 genus, 179 species, 1 subspecies, 30 varieties and 5 forms in 1989. The number of floristic regional indicator plants was 58 taxa with 1 taxa of level Ⅴ and 11 taxa of level Ⅲ, 46 taxa of level Ⅰ. Endermic plants of Korea were surveyed such as Forsythia koreana, Populus tomentiglandulosa, and Paulownia coreana ; rare plants were surveyed such as Prunus yedoensis, Chionanthus retusus but planted. Also, naturalized plants were recorded as 23 taxa, 10 families, 19 genus, 23 species; Naturalization Index 6.82% and Urbanization Index 7.6%. In conclusion, this study was the distribution of vegetation of variety climatic zone(temperate zone, warm temperate zone) in small areas of the Song-i-do. And it was to provide primary data in order to contribute to the conservation and restoration of flora and vegetation. Also, it was to be necessary to control the non-native species and protect the native plants species.