<p>We have established ecological research plots in the laurel forests of Amami-Oshima Island and Tokunoshima Island, which are candidates for World Natural Heritage sites, and are constructing a monitoring system for flora and fauna. In this study, we conducted a survey to understand the relationship between clear cutting history and/or microtopography and species diversity mainly in the forest area outside the national forest where ecological knowledge is scarce in the laurel forest of Amami-Oshima. As a result, we found that although laurel forest in the upper slope area near the ridge and the lower slope area facing the deep valley had some common species, there were some species with distinctly different distribution patterns. In particular, many species of forest floor herbs, such as ferns and orchids, were distributed in the lower slope area. In addition, many epiphytic plants which included many endangered species were found in the unlogged forest areas. The relationships between number of sites and the cumulative number of species showed that the species composition of the unlogged forests in the lower slope area differed greatly between forest stand, suggesting that beta diversity contributed significantly to the overall species diversity. On the other hand, some deciduous trees had a biased distribution in the logged areas, and some tree and shrub species preferred in the upper slope areas such as ridges. These results suggest that in order to maintain the species diversity of plant species in the entire watershed, it is essential to have a habitat on each microtopography of slope from the ridge to the valley.</p>