Bethylus Latreille, a type genus of the family Bethylidae, is represented by about 32 species and is recorded fromthe Palaearctic and the Nearctic regions. In East Asia, the genus has been reported from Far Eastern Russia, China andJapan. The genus was well-known as ectoparasitoid of micro-lepidopteran insects including gelechiids, coleophorids.As results of taxonomic study on Korean Bethylinae, the distribution of Bethylus is newly confirmed in South Koreaand the species was identified as B. fuscicornis (Jurine, 1807). We provide the description, diagnostic illustrations of B.fuscicornis and a key to Korean genus of Bethylinae.