Glycine tomentella， which belongs to Glycine subgenus of Glycine Willd.， is a secondary protected wild plant species in China. It is distributed in coastal areas of Fujian and Guangdong provinces and their adjacent islands. As a valuable genetic resource for soybean breeding， it has experienced population declines in recent years due to land development， herbicide overuse， environmental changes and other anthropogenic pressures in its native habitats. Therefore， understanding its plant community composition and structural characteristics is critical for developing effective protection strategies for this species. In this study， 50 G. tomentella plant communities were surveyed across the coastal zones of Fujian and Guangdong provinces. The ecological data of plant composition， plant density and average plant height of 255 quadrats （1 m×1 m） were investigated， and the species diversity， interspecific relationship and niche characteristics of the communities were analyzed. The results showed that： There were significant differences in the plant composition of G. tomentella community between Fujian and Guangdong provinces. A total of 166 species （138 genera and 48 families） were recorded， including 123 species of herbaceous plants （74.10%）， there are 53 species belonging to 45 genera， 23 families unique to Fujian province and 70 species belonging to 64 genera， 27 families unique to Guangdong province. The two provinces shared only 13 dominant species， and there are significant differences in the composition of plant communities. The interspecific association degree of the community species in Fujian province was higher than that in Guangdong province， and the distribution of species was more uniform at the quadrat level. The niche breadth of Imperata cylindrica and Cynodon dactylon in Guangdong province was much higher than that in Fujian province. The species with higher niche overlap differed entirely between the two communities， indicating geographical adaptability in niche traits. These results revealed mostly non-significant negative correlations， suggesting that the species were basically independent. The communities in the two provinces appear to be in an unstable state， underscoring the need for region-specific conservation.