The Twelve taxa of the Bidens L.(Asteraceae) in Korea were reported. Bidens tripartita L. var. repens (D. Don) Sherff was known to be distributed in some mountain wetlands such as Nepal, South Korea, and has also been found growing in China and Japan. This taxon in Korea was collected from Mt. Halla in 1900, by Emile Joseph Taquet, but until recently for information on these taxa is incomplete. It is distinguishable from Bidens tripartita L. var. tripartita by characteristics such as decumbent, stems 5-20cm, almost glossy bodies with smooth margins. This taxon was discovered Mansedong-san(alt. 1633m), Sumeunmulbaeng-dui wetland(alt. 963m) and 1100 Highland wetland(alt. 1100m) from Mt. Halla in Jeju. Bidens tripartita var. repens Sherff is identified EN(Endangered species) as a candidate, according to IUCN Red List Criteria(ver. 3.1).