Genus Trissolcus are considered as most effective natural enemy for control Pentatomid pests. Trissolcus japonicus (Ashmead) is native egg parasitoid of the brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) in Palearctic region. Nevertheless, identification of Palearctic Trissolcus species are still controversial because of morphological homogeneity such as Trissolcus semistriatus (Nees, 1834) and Trissolcus Kozlovi Ryakhovskii, 1975. This study reassessed Korean Trissolcus species diversity and provided DNA barcoding data using mitochondrial cytochrome c oxidase subunit I (COI) gene for 11 Korean Trissolcus species.