Abstract
Up to the present, four Hahnia species are known from Japan: H. corticicola, H. martialis, H. nava and H. pinicola. Further two species are newly recognized in Japan. One is new to science, described as Hahnia tanikawai sp. nov. The other, H. thorntoni is newly recorded from Japan. These two species are easily distinguishable from the other congeners by their copulatory organs.