Ohioglossum petiolatum (Ophioglossaceae) was newly found in Song-do (island), Okdong-ri, Hwangsan-myun, Henam-gun of Chullanam-do. This species had not been ascertained yet in Korea. The description and figure of O. petiolatum was provided based on the new information in Korea. The Korean names of four taxa of Ophioglossum(Ophioglossaceae) was revised.