Eight species belonging to two genera of the Laboulbeniales, parasitic on the family Carabidae and Staphylinidae of the order Coleoptera, were collected from Upo natural swamp in 1996-2001. They are as follows; Laboulbenia anoplogenii parasitic on Platynus daimio, L. cristata on Paederus parallelus, L. egens on Tachys laetifica, L. flagellata on Platynus daimio, L. pedicellata on Bembidion morawitzi, L. philonthi on Philonthus wuesthoffi, L. stenolophi on Acupalpus inornatus and Philonthus longicornis, and Peyritschiella biformis on Philonthus micaticollis. Among these species, the genus Platynus as the host of L. anoplogenii and the genus Acupalpus as the host of L. stenolophi are new to science. Bembidion morawitzi as the host of Laboulbenia pedicellata and Philonthus micanticollis as the host of Peyritschiella biformis are new to Korea.