The chiropteran fauna of Oze district, a mountainous part of Nikko National Park, has hitherto been poorly known, and represented by only two species of bat, Murina aurata ussuriensisandMyotis ozensis. The author studied the area in the summer of 1973, 1974, 1978 and 1979, and obtained following five species of bats in mixed forests of beech, oak and conifer; Myotis hosonoi, Myotis frater kaguyae, Nyctalus furvus, Plecotus auritus sacrimontisandMurina aurata ussuriensis.Among themMyotis hosonoiandPlecotus auritus sacrimontiswere most common and seemed to be dominant species in the area. All of the specimens ofNyctaluswere caught in the mist nests at about 7m in height from the ground, those ofMurinaat about one meter or less, andMyotisin the medium parts between them. From this evidence, it is estimated that those three species have segregated hunting zone, differing in height in the same forest.