The study performed flora investigation for 3 times on seasonal basis between April and October 2012 in Seongeup Folk Village, Pyoseon-myeon, Jeju-si designated as No. 188 of the National Major Folk Cultural Asset to analyze distribution and features of alien plants and categorized naturalized plants to calculate the naturalized index and the urbanization index. The tracheophytes of the village is 201 taxa including 80 families, 175 genus, 183 species, 14 varieties, 2 plants and 2 subspecies and the alien plants account for 32.8% with 66 taxa including 37 families, 60 genus, 63 species, 2 varieties and 1 subspecies and the naturalized plants have a total of 27 taxa including 14 families, 24 genus, 26 species and 1 variety. The naturalized index of the 321 taxa of the naturalized plants was 13.4% and the urbanization index was 8.4%. Systematic plans to manage plants in the Seongeup Folk Village are required, as well as gradually eliminate alien and naturalized plants and replace them with indigenes.