Sequence variation of ribosomal regions, namely the second internal transcribed spacer region of the nuclear ribosomal gene cluster (ITS2), the D2 domain of 28S ribosomal subunit (28SD2), and the mitochondrial cytochrome oxidase I (COI) were examined for differentiation of Trichogramma euproctidis Girault and Trichogramma brassicae Bezdenko (Hymenoptera: Trichogrannmatidae) populations. The length of ITS2 region ranged from 378 bp to 406 bp. The sequences of 28SD2 and COI were 522 bp and 669 bp for T. euproctidis and 530 bp and 672 bp for T. brassicae, respectively. A phylogenetic relationship was constructed by using the maximum likelihood method for each marker. The ITS2 gene region more clearly differentiated between T. euproctidis and T. brassicae than the 28SD2 and COI genes.