To study the mechanisms of succession and species coexistence in this forest type, a 11.56 hm² forest plot in the Yaoluoping Nation Nature Reserve was established according to the CTFS technical standards. In this plot, all free-standing trees with DBH (diameter at breast height) ≥ 1 cm were mapped, tagged, and identified. Preliminary results on floristic characteristics, community composition, species diversity and interspecific associations were determined and discussed in this study. The results showed that:(1) There were 24910 individuals, which belonged to 103 species, 57 genera, and 35 families. The eight most dominant families were Rosales, Aceraceae, Aquifoliaceae, Lauraceae, Ericaceae, Betulaceae, Saxifragaceae, and Fagaceae. (2) In the sample plot, the species diversity was distributed evenly. The four most dominant species were Castanea seguinii, Carpinus turczaninowii, Symplocos paniculata, and Dendrobenthamia var. chinensis. The trees were distributed at all heights, but mainly between 2 m and 8 m. (3) The χ² test showed there was a significant correlation among 32 species pairs of 105 species pairs. The analysis of the AC results revealed that among the 105 species pairs of the 15 dominant populations, 49.2% had significant positive correlations and 24.8% had significant negative correlations, and the association intensity was concentrated at relatively low levels, which indicated that the community structure was still in the growth stage.