Both abiotic factors and biological factors affect growth of wetland vegetation. Of the former hydrological and soil environmental factors are the major ones and hence the hot spots and focal points of the research on wetland eco-hydrological processes. Investigations were carried out of variation of various soil environment factors in content in shoaly wetlands typical to the Poyang Lake under four different kinds of plant communities, and CCA (Canonical correspondence analysis) ordination was performed of the 20 vegetation sampling plots in the research zone, for analysis of major soil environment factors in the shoaly wetlands and their effects of vegetation distribution. Results show that the soils under four kinds of vegetation communities differed sharply in total nitrogen (TN) content, displaying an order of Carex cinerascen < Artemisia selengens+Cynodon dactylon Phragmites communis Carex cinerascen < Phalaris arundinace Carex cinerascen, and demonstrated a similar trend in variation of total organic carbon (TOC), for these two were significantly positively related. They did not have any significant trend of variation in soil total phosphorus (TP) content. With the increasing distance of the shoaly wetlands from the water body of the lake, content of readily available potassium (AK) in the soils showed an increasing trend, but not great in extent. Soil total nitrogen and soil available phosphorus (AP) was closely related to soil organic carbon and soil available phosphorus was significantly negatively related to soil moisture (SM) content, while content of available phosphorus was significantly related to total nitrogen. To sum up, soil moisture content is the major factor and soil pH and total potassium (TK) content are also important ones among the soil environment factors affecting distribution of vegetation on wetland soils.