Abstract: In order to understand the temporal dynamics of community structure and biodiversity of the representative vegetation of Pinus tabulaeformis in the Laojunshan National Nature Reserve in Henan Province, a plot investigation was carried out in the year of 2018 and 2023 in P. tabulaeformis stand. The results showed that within 5 years, tree density in the P. tabulaeformis stand decreased, the community species decreased from 70 families, 124 genera, 146 species to 57 families, 94 genera, 131 species. The number of common species and occasional species decreased from 104 and 42 to 93 and 38, respectively; P. tabulaeformis and species of Genus Quercus, Castanea and Acer still maintain dominance, but the important value of P. tabulaeformis decreased much. The plant individual distribution along with both the DBH(diameter at breast height) and tree height shows an inverted "J" shape, but as of P. tabulaeformis, shows a partial normal and bimodal distribution. The seedling and young number of P. tabulaeformis is relatively small, and it may decline in the future. The species richness and species diversity of tree layer of the community decreased, while the species diversity of the shrub layer and herb layer increased. Research indicate that the community structure and its biodiversity of the P. tabulaeformis stand has changed within the 5 years, there is a great possibility that P. tabulaeformis may decline and be replaced in the future.