1) In this paper are described a sociological study on the sturcture and floristic composition of epiphyte communities consisting of lichens, bryophytes and vascular epiphytes, which communities range from the trunk-bases to the uppermost part of crowns of beech trees (Fagus crenata BLUME) in the beech forests growing on about 860-1160 m alt. of Mt. Hiko, Japan. 2) Sample-trees, on which epiphyte communities developed, were chosen 29 ; 10 (No. 16-25) growing on the peak, 7 (No. 4,8,9,11,13-15) on ridges, 8 (No. 1-3,5-7,10,12) on slopes and 4 (No. 26-29) in a ravine. The investigations were taken place in the summers of 1952 and 1953 by using frames of quadrat, according to CAIN's method with the minimal area and minimum number of quadrat. A number of frames were laid on epiphyte communities from the trunk-bases to the crowns. 3) We recognized 5^* epilias of epiphyte communities (Table 2) which grow on the beech trees in the forests ; the Thuidium cymbifolia-Homaliodendron scalpellifolium epilia, the pterobryum arbusculla-Anomodon Giraldii epilia, the Graphis sp. 1-Pertusaria sp. 1 epilia, the Cetraria collata f. nuda-Boulaya Mittenii epilia and the Ulota crispa-Pertusaria sp. 2 epilia. 4) No vascular epiphyte predominates over lichens and bryophytes in any epiphyte community, so that vascular epiphytes are usually subordinate to bryophytes and lichens on the trees in the forests.