Mount Badagongshan (BDGS) National Nature Reserve is located in the northern margin of Wuling Mountain, which harbor large areas of evergreen and deciduous broadleaved mixed forests. These forests have high species diversity and possess a complex community structure. In 2010-2011, a 25 ha (500 m × 500 m) forest dynamic plot was established in this reserve according to the standards of the Center for Tropical Forest Science (CTFS). Within this plot, all woody plants with DBH ≥ 1 cm were mapped and identified to species level. Based on these data, we analyzed community composition and spatial structure of the vegetation community. We found 186,575 individuals in the plot, belonging to 53 families, 114 genera and 232 species. There were 38 species that had > 1,000 individuals each and these species comprised 87% of total abundance. The most abundant species was Litsea elongata. There were 103 rare species, i.e. with ≤ 25 individuals, which accounted for 44% of all woody species but only made up 0.4% of the total abundance. Across all individuals in the plot, the average DBH was 5.41 cm. Individuals with DBH ≤ 5 cm accounted for 68.4% of the overall abundance and the 7,474 individuals with DBH ≥ 20 cm accounted for only 4% of the overall abundance. The frequency distribution of DBH appeared to have a reverse “J” shape, suggesting that the community was maintaining successful regeneration and normal growth patterns. The number of species increased linearly with increasing area. When the sampling area was increased to 10 ha, we recorded 201 species, which represented more than 90% species of the entire plot. These 1-ha samples had average abundance of 7,261.8 ± 974.8 (SD), average species richness of 128.2 ± 8.2 (SD), average of 3.56 ± 0.11 (SD) for Shannon-Wiener index, and 1.69 ± 0.06 (SD) for Pielou evenness index. There was no significant relationship between abundance and the diversity indices, suggesting that instead of the sampling effect, some other mechanisms affected the species diversity pattern in BDGS plot.