Abstract: The dynamic analysis of the community structure reveals the tree growth patterns, renewal processes and changes in the age structure of Pinus massoniana forests at different growth stages. The dynamic analysis of biomass is of great significance for understanding the ecological functions of forests and formulating management strategies. Affected by pine wilt disease, climatic variation, human activities etc., P. massoniana forests have confronted a series of challenges over recent years, the community structure of which has changed significantly. In this study, the community dynamics and biomass of P. massoniana forests in Chun’an County were explored through along-term monitoring. The results showed that there was a 68% decrease in the number of sample plots of P. massoniana forests from 2010 to 2024, while that of coniferous-broadleaf mixed forests increased remarkably, and the community evolved towards coniferous-broadleaf mixed forests. DBH (diameter at breast height) and tree height of P. massoniana forests increased by 24.13% percent and 15.40 percent respectively, showing the slow increasing trend, whereas those of the coniferous-broadleaf mixed forests dropped by 14.73% and 8.90% separately with the downward trend. Regarding the diversity index, the richness of coniferous-broadleaf mixed forests increased, those of P. massoniana forests and broadleaf forests changed. The biomass of P. massoniana forests and broadleaf forests increased by 59.10% and 25.31% respectively, with a decreasing rate of 18.30% of coniferous-broadleaf mixed forests form 2018 to 2024. There were large differences and obvious changes in the biomass of arbors, shrubs and herbs among different forest types. The research results reveal the dynamic change regularity of the P. massoniana forest community, providing a scientific basis for the management and protection of forest ecosystem.