Population structure and spatial patterns are closely related to the ecological characteristics of a species and are important for determining the formation and maintenance mechanisms of a community, especially the spatial pattern of dominant species. Spatial point pattern analysis based on the location of plant individuals is a widely used and powerful method. Marked point pattern analysis introduces individual characteristic variables into point pattern analysis, such as diameter at breast height (DBH), height, and biomass, which can provide additional information about vegetation for further research. Biomass is an important quantitative characterization of the energy flow in a forest ecosystem, and its spatial distribution isclosely related to biodiversity. The objective of the present study was to investigate both individual and biomass patterns of the dominant species in a forest, to draw inferences onpopulation dynamics and reveal the mechanisms of species coexistence from a biomass perspective, and to explore the application of marked point patterns in forest ecology research. The study sites were located in the Guangdong Kanghe Provincial Nature Reserve (23°44' to 23°53' N, 115°04' to 115°09' E). We established a 4 hm² (200 m×200 m) permanent sample plot in a subtropical evergreen broad-eaved forest. All individual trees with DBH≥1 cm within the plot were measured and mapped. Castanopsis carlesii and Schima superba were the dominant species in the community, with the highest importance values (20.57% and 12.81%, respectively). The age structure of C. carlesii and S. superba was analyzed. Using Ripley's L function and the mark correlation function, we determined the spatial point pattern of individuals and biomass visually. The results were as follows: The age structure of C. carlesii and S. superba was pyramid-shaped with a large number of seedlings, indicating that both populations were expanding. Both populations showed an aggregated distribution at the scale of 0-50 m, suggesting that habitat heterogeneity played a vital role in the formation of the population spatial pattern. The aggregation intensity of the C. carlesii population increased as the spatial scale extended, whereas the S. superba population aggregated gradually at the 0-9.5 m scale and then decreased at higher spatial scales. The biomass of C. carlesii showed a negative correlation among individuals, which indicated that intraspecific competition for resources was significant. The S. superba individual biomass was independent, showing that intraspecific competition was not significant. The spatial patterns of biomass indicated that S. superba, a subtropical pioneer tree species, was more efficient in resource use.The percentage of large trees was much higher in the C. carlesii population, and large trees competed intensely for resources such as light and space. The biomass distribution pattern was uncoupled with the individual distribution pattern for these two populations. However, analysis of individual and biomass spatial distribution patterns both implied that the distribution pattern of the two populations was conducive to species coexistence.Marked point patterns and spatial point patterns can complement or test each other when exploring the maintenance mechanism of biodiversity. In the future, forest health and other indexes for forest management can be used as marks in marked point pattern analysis, which has broad prospects for application in monitoring forest dynamics and quantifying ecological processes.