According to the world floral region, Hallasan belongs to the temperate subregion with Yangtze River basin and southwest Japan. From the coast to the top of the Hallasan, plants are distributed vertically from the subtropical plants to the alpine plants due to the environmental gradient. Of the 4,000 species of vascular plants native to Korea, about 400 species are estimated to be endangered or potentially rare. Especially, 23 species-specific wild plants designated by the Ministry of Environment ( totally 59 species ) are distributed in Jeju Island and 6 of them can be found in the natural reserve area of Hallasan. Also, about 50 kinds of special plants are distributed in Jeju Island, especially in the highlands of Hallasan.