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.

One species of the genus Coleopius (Hymenoptera: Braconidae: opiinae) are reported in this study. The genus Coleopius is a small braconid group distributed in the Palaearctic and Oriental regions, which has three species in the korea in current. In this study, Coleopioides postpectalis Li and van Achterberg is recognized for the first time in South Korea, which had been recently recorded from China. Descriptions, diagnosis distribution and illustration are provided

Two species of the genus Asiacentistes (Hymenoptera: Braconidae) are reported in this study. The genus Asiacentistes is a small braconid group distributed in the East Palaearctic and Oriental regions, which has only two species in the world. One of them, Asiacentistes sinica Chen and Belokobylskij is new to Korea. Diagnosis and distribution in East Asia data are included.

Two species of the genus Cosmophorus (Hymenoptera: Braconidae) are reported in this study. Members of Cosmophorus are known as solitary koinobiont endoparasitoids of adults of barkboring and woodboring Scolytidae. The genus Cosmophorus of the subfamily Euphorinae is small in the size and enigmatic in the ecology, which has been recorded in Holarctic, Oriental, Afrotropical and Australian regions. Only five species are known in East Palaearctic. Among them, Cosmophorus (Cosmophorus) klugii Ratzeburg is new to Korea. Diagnosis and distribution data are included.

Two species of the subgenus Exosyntretus (Hymenoptera: Braconidae: Euphorinae) in the genus Syntretus are reported from Korea in this study. The species of the genus Syntretus are small parasitic wasps, which attack adult Hymenoptera. Their hosts are adult parasitoid wasps and adult bees. The subgenus Exosyntretus are known as only five species in the world. Among them, Syntretus (Exosyntretus) nevelskoii Belokobylskij is new to Korea. The world checklist, diagnosis and distribution data are included.