In Taiwan, Fagus hayatae Palib. ex Hayata (Taiwan beech) is of particular interest because of its limited and relic-like distribution within the Lalashan Nature Reserve in northern Taiwan. It forms nearly pure stands extending about 18 km along the ridges at elevations of J,300 to 2,000 m. Three stands, representing northern, middle, and southern ranges of the beech forests, were sampled using thirty-two lOX 10 m q~adrats. They were surveyed for physiognomy, structure and flori stic composition. About 172 species of vascular plants were encountered. Species richness per plot averaged 39. Diversity of trees with a DBH > 1.0 cm was calculated as Shannon-Wiener index (2.34) and Simpson index (0.12). The density was 5700 stems with an average basal area of 56 m1 per ha. The beech contributed more than 76% of the total basal area. Other important species were Rhododendron formosana and Enkianthus perulatus in the subcanopy layer. ln the understory, Yushanian niitakayamensis (dwarf bamboo) usually formed extremely dense layers. Sum of square agglomerative cluster analysis led to the recognition of 3 vegetation types. Reciprocal averaging ordination of the plots suggested a vegetational continuum in response to topographic gradient. Size-class distribution of the beech indicated a unimodal pattern wi th underrepresentation exhibited in the smallest size-class; however, variation among sampling locations might be present. It also suggested that Taiwan beech was likely to be shade-intolerant. In terms of physiognomy and generic composition, closest affinity appeared to be with the Fagus lucida forest of Mt. Fangchingshan in southeastern China.