In order to clarify the species composition, distribution and habitat of the Korean wild Pyrus ussuriensis and P. pyrifolia communities, that are so expected as a useful resource plant, an investigation was carried out according to phytosociological method on Mts. Hambaek, Ilwol, Sobaek, Juwang and Gaya in Korea. In the present study, we made an attempt to elucidate the autecological characteristics of the wild Pyrus species by synecological approach. As a result, the forests including the Pyrus species were divided into the two associations and two communities, considering the existing vegetation units for the forest; Syneilesio-Quercetum serratae, Corylo-Quercetum mongozicae, Ainsziaea acerifolia- Quercus mongolica community and Fraxinus rhynchophylla-Pyrus ussuriensis community. Among the units, the Syneilesio-Quercetum serratae and the Corylo-Quercetum mongolicae belong to southern type and middile-northern type, respectively, in their distributional type. It is inferred that the wild Pyrus species are distributed preferably in the deciduous forest zone in Korea, compared to the other forest zones. In particular the Pyrus species are present alone or dominantly in only both the tree layer or subtree layer of the forests, reflecting their shade intolerance ecophysiologically. Thus they usually were distributed in SE or SW of slope aspect. Generally the canopy of the forests including the Pyrus species was so open. Species diversity of the vegetation units was highest in the Syneizesio-Quercetum serratae and lowest in the Ainsliaea acerifolia-Quercus mongolica community. The Corylo-Quercetum mongolicae and the Pyrus ussuriensis-Fraxinus rhynchophylla community are medium between the two.