This study was carried out to investigate the distribution of vascular plants and their usefulness in Mt. Ilsan (Hwacheon-gun, Gangwon-do). The vascular plants were summarized as 496 taxa; 91 families, 295 genera, 422 species, 1 subspecies, 58 varieties, and 15 forma. Among the investigated 496 taxa, 17 Korean endemic, nine rare, and one endangered plants were included. Based on the list of the species of specially designated plants by the Ministry of Environment, 66 taxa including Hanabusaya asiatica and Aconitum koreanum were recorded in the investigated area. The naturalized plants were identified as 27 taxa and the percent of naturalized plant species(PN) was 5.4% of all 496 taxa vascular plants. Usage of 496 taxa were consists of 201 taxa(40.5%) of edible plants, 168 taxa(33.9%) of medicinal plants, 69 taxa(13.9%) of pasture plants, 61 taxa(12.3%) of ornamental plants, 17 taxa(3.4%) of timber plants, 16 taxa(3.2%) of fiber plants and 4 taxa(0.8%) of industrial plants.