Japanese giant salamanders Andrias japonicus inhabit the Mukunashi River around Higashi-Hiroshima City in Hiroshima Prefecture, southwestern Japan; researchers and local people have collaborated to investigate the species’ behavior, particularly its oviposition and the movement of larvae after leaving the nest. In this research we focused on leaf litter in the stream as habitat in which salamander larvae and the aquatic insects which are its critical food cohabit. We studied the flora of the riparian forest to identify the species of leaf litter in the stream among which salamander larvae were found. Leaf litter and branches belonging to 29 species of vascular plants were identified, and most leaves were from the deciduous oak Quercus serrata and the conifer Cryptomeria japonica. It is suggested that the surrounding flora has an important influence on the survival of Japanese giant salamander larvae that have left the nest.