Decomposition of recalcitrant compounds such as lignin determines decomposition of leaf litter and results in the occurrence of bleached area on leaf litter. It is unclear how climatic conditions affect colonization and decomposing activity of ligninolytic fungi that causes bleaching of leaf litter and species richness of ligninolytic fungi associated with leaf litter decomposition. Purpose of the present study is thus to examine the pattern and difference of bleached area on leaf litter of Betula ermanii and Quercus crispula along an altitudinal gradient on Mt. Rausu in Shiretoko Peninsula. Leaf litter of B. ermanii and Q. crispula were collected from old-growth forests at 200, 400, 600, 800, and 1000m a.s.l. and measured for bleached area and fungi. Bleached area was smaller on B. ermanii than on Q. crispula. Bleached area on B. ermanii was significantly lower at 800m and 1000m than at 600m, suggesting that cooler climate retarded the colonization of ligninolytic fungi. Altitudinal difference was not detected on Q. crispula. Bleaching of B. ermanii was enhanced by direct contact to Q. crispula leaf litter, suggesting that lack of Q. crispula at 800m and 1000m can also be responsible for the lower bleached area on B. ermanii.