Relationships between microhabitats and vegetation structure were examined in a 1-ha plot established in an evergreen broadleaf forest at Mt. Peitunyen, central Taiwan. Parameters of various growth types (trees, shrubs, and herbs) were recorded. The elevation, irradiance, soil organic matter, soil pH, soil total carbon, soil total nitrogen, and tree basal area were determined. This study classified vegetation types by a two-way indicator species analysis (TWINSPAN), and verified them by a detrended correspondence analysis (DCA). The research area belongs to the Meliosma callicarpifolia-Castanopsis cuspidata var. carlesii association, which could be subdivided into 3 subtypes. The Machilus thunbergii-Lithocarpus amygdalifolius subtype was distributed in higher and less-fertile habitat. The Ilex goshiensis-Lithocarpus amygdalifolius subtype was distributed in more-fertile habitat. The Ilex ficoidea-Machilus japonica subtype was distributed in lower and less-fertile habitat. The degree of soil fertility, basal area of trees, and elevation affected the plant species number, average plant density, and average basal area of each subtype.