Abstract:Plant species diversity of Sinocalycanthus chinensis community in Dalei mountain of Zhejiang Province was determined by using the index of species richness, species diversity and community evenness, and the relationships between the biodiversity indices and soil factors were studied by employing correlation analysis. According to the statistics of ten plots, there are altogether 74 families of vascular plants which can be subdivided into 193 species, 165 genera. Most of them are distributed in the temperate zone in terms of the geographic composition of seed plant genera. In different communities, the species richness and species diversity index of the woody plants were highest in Cunninghamia lanceolata+Schima superba forest, the community evenness was highest in C.lanceolata forest, and these index were lowest in bamboo grove. The species richness of the herbal plants was highest in C.lanceolata+Pinus massoniana forest and lowest in C.lanceolata forest. The species diversity index and community evenness of the herbal plants was highest in bamboo grove and lowest in Quercus serrata var. brevipetiolata+Eurya muricata forest. In the vertical structure of these different communities, the species richness and species diversity index of tree layer were lower than those of shrub layer, the species diversity of herb layer was greatly varied in different communities. The correlation analysis showed that there was great correlation existing between the species diversity of S.chinensis community and soil organic matter content in which organic matter content was positively related to species diversity of the woody plants but negative to the herbal plants significantly, respectively.