Abstract: The author analyzed dominant population structure and distribution pattern of the Heptacodium miconioides community in the Tiantai Mountain of Zhejiang Povince. The results showed that the age-class in majority dominant populations of the community was incomplete and the age structure was declining, and that the Heptacodium miconioides forest was an unstable community; that the distribution patterns of dominant populations in various plots were of clump distribution. Using veriance ratio(VR) and x² text by 2×2 contingency table, the paper analysed the overall relatedness between 18 major tree varieties of the tree-layer and 20 major varieties of the shrub-layer, and the interspecific association. It hence came to the following conclusion:In the tree-layer, there was unremarkable positive relatedness on the whole, and there were more species pairs of positive association than those of negative association; There was remarkable positive relatedness among the major tree varieties of the shrub-layer, and there were obviously more species pairs of positive association than those of negative association.

Key words: Heptacodium miconioides, population structure, distribution pattern, interspecific association, Tiantai Mountain