The mandible character of the Lucanidae is vary by considering of developmental difference in male individual specimen. Especially, species of Genus Cyclommatus Parry, 1862 presents strong mandibular allometry. In this research, The species group which related to Cyclommatus montanellus Möllenkamp, 1904 has been evaluated for the first time in this research with inner teeth composition and positioning to establish clear taxonomic key to each species.