Some euryalid specimens were collected with fishing nets from Mipo, Gyungsangnamdo and Aewol, Jejudo Island, Korea. They were identified as Gorgonocephalus eucnemis (Müller & Troschel, 1842), belonging to family Gorgonocephalidae of order Euryalida, which was new to the Korean fauna. Their molecular analyses were done with newly intended COI primers of mitochondrial cytochrome oxidase I (COI) gene for the accurate molecular identification. The Korean G. eucnemis was coincident with this NCBI species as a result of Blast analysis, which showed the 99% similarity. In the current study, three Gorgonocephalus species have been reported from Korea.