The fungal communities associated with the roots of Vaccinium species (Ericaceae) along an elevation gradient were investigated. The study was conducted on a north-facing slope on the Kiso Mountaions, Nagano, Japan in September 2010. The fine roots of Vaccinium were sampled at five sites at different altitudes (c. 1600, 2000, 2300, 2700 m). Two different vegetation sites (a Pinus pumila shrub site and an open site) were established at 2700 m. Five Vaccinium trees (1600 m: V. smallii, 2000 m: V. yatabei, 2300 m: V. ovalifolium, 2700 m: V. vitis-idaea) were selected on each site. The fine roots by the surface sterilization technique with 0.1% aqueous solution of mercuric chloride. 24 segments (c. 5mm long) were cut off from the roots and plated out on the corn meal agar with chloramphenicol and incubated at 15 ℃ for about one month in the dark and observed with a microscope at proper intervals. Isolated cultures were identified by both morphological observation and molecular analysis. The 235 isolates obtained were assigned to 27 OTUs. 78 % of the OTUs were belonged to Leotiomycetes. The number of isolates and fungal species decrease with altitude when Vaccinium species were distributed as understory vegetation. The OTUs composition changed in a characteristic manner.