Abstract:The species composition and diversity, as well as the inter-community similarity of four successional forest communities in Zhejiang province, including coniferous forest (pine), coniferous (pine) and broad-leaved mixed forest, mid-aged evergreen broad-leaved forest and pre-matured evergreen broad-leaved forest, were investigated by chronosequences and quadrat methods. The results showed that, there were 170 vascular species belonging to 53 families, 105 genera in the 23 plots. Along with the disappearance of pioneer species and appearance of later successional species, the trends of species richness and Shannon-Wiener index of three layers both decreased and then increased with the succession, and the coniferous and broad-leaved mixed forest had the lowest species diversity. The Jaccard similarity indices of four communities decreased along the successional sequence. Among them, the similarity index of pine coniferous forest and pre-matured evergreen broad-leaved forest was the lowest, and the principal component analysis showed the similar result. The differences among four communities were mainly presented in the species composition, especially that of tree layer. The coniferous and broad-leaved mixed forest had lower species richness and diversity, but it had higher similarity with other forest types, and stored most species of the later successional stage-evergreen broad-leaved forest, suggesting it is a key stage in the succession.