We report here one species, Ampelodesmus cf. granulosus myrmecophilus millipede (Pyrgodesmidae) collected fromcolonies of Brachyponera chinensis (Formicidae: Hymenopera). The family Pyrgodesmidae contained over 500 speciesdistribute mainly in tropics (Shear, 2011). Some species are found only in ant colonies, and are considered obligate myrmecophiles(Stoev et al. 2005). Myrmecophilus pyrgodesmid millipedes are known to scavenger as they feed on debris of host ants.Largely unknown is how millipedes can avoid from aggression of host ants, but host ants completely ignoring their invader(Komatsu, unpublished data). Two genera and four species of family Pyrgodesmidae were known from Japan which werecompletely unknown from South Korea. In this study, we provide description, especially gonopods of male, host informationand breeding records of Ampelodesmus cf. granulosus.