The objective of the study was to investigate vascular plants of Mueuido in Incheon from April to October, 2011. The investigation was carried out for mountains (Mt. Horyonggok and Mt. Guksa), coastal areas and annexed islands (Silmido and Somueuido). Vascular plants were found to have 338 taxa, including 90 families, 235 genera, 297 species, 5 subspecies, 32 varieties and 4 forms. Rare and endangered plants designated by Korea Forest Service had 5 taxa including Utricularia bifida, U. vulgaris var. japonica, U. racemosa, Ottelia alismoides, and Arisaema heterophyllum. The floristic regional indicator plants found in this area had 3 taxa of grade V and 5 taxa of grade III. Naturalized plants consisted of 20 taxa that made up 8.3% of the total vascular plants in this area.