Interactive effects exist among soil, vegetation, hydrology and climate in wetland areas, affecting the charateristics of wetland ecosystems. Wetland soil is usually a product of long-term interactions between ecological environment factors and plays a vital role in preserving the regional ecological balance. The factors that influencewetland vegetation include biological and abiological variables, which soil of abiological variable has the most profound effect on wetland plant growth. Relationships between wetland plants and soil have always been a hot topic in ecology and also form the basis for plant population niches research. Based on a sample plot-species matrix of Importance Value (IV) of 20 species at 19 sampling plots in the Chayegang marshland of the Poyang Lake region near Henghu farm, we used the Ward cluster method of hierarchical clustering to divide the plants in the study area into 3 community types-Com. Carex cinerascens, Com. Phalaris arundinacea and Com. Triarrhena lutarioriparia. Spearman rank correlations results revealed that, when considering biodiversity indices (Shannon Wiener diversity index H', species richness index S and Pielou evenness index J) and soil factors (soil pH, electrical conductivity, moisture and organic matter), there were significant positive correlations (P < 0.05) between H' and soil pH, and highly significant positive correlations (P < 0.01) between S and soil pH; However, there were significant negative correlations (P < 0.05) between H' and soil organic matter and highly significant negative correlations (P < 0.01) between S and soil organic matter. However, the Pielou evenness index J had no discernible correlation with soil factors. The relationships of plant species distribution with soil pH, electrical conductivity, moisture and organic matter were assessed using redundancy analysis (RDA); Results revealed significant relationships of plant distribution with soil pH and soil organic matter (P=0.042 and 0.048), which were regarded as the key soil factors that controlled species distribution.As soil pH and organic matter were determined to be the principal environmental factors that had a considerable influence on plant species distribution, both were divided into 10 gradient levelsto analyze the plant population niches. The results showed that the dominant species, C. cinerascens and P. arundinacea, had larger niche breadths, while Veronica peregrina, Nymphodes peltatum, and other specieshad smaller niche breadths. All plant species in the study area had relatively small niche overlaps on the whole, suggesting that the population niches had obvious differentiation in soil pH and soil organic matter gradients.