The genus Japanolaccophilus Satô in small groups belonging to the subfamily Laccophilinae of the family Dytiscidae. However, members of this group have not been recorded in the Korea. The genus Japanolaccophilus Satô is characterized by the following features: suture between elytron and epipleuron visible dorsally, posterior angles of pronotum rounded, posterior margin of pronotum nearly straight, and posterior part of prosternal process triangula and with single tip in middle. We collected specimens from the edge of Osip Stream and identified the species of Japanolaccophilus niponensis (Kamiya, 1939) for the first time based on male genitalia. A habitus photograph, a description, illustrations of the aedeagus and information of habitat are provided.