The aim of the present study was to determine the variation in vegetation distribution patterns, diversity indices, and soil characteristics under water level elevations in land and water ecotones, in the northern part of Gonghu Bay in October 2015. Observing and records of phytocoenosium formations and soil features showed that the majority of all 165 species, subordinated to 142 categories and 65 families, were perennial plants that were seriously affected by human activities. The higher the water levels, the higher the abundance of plant communities (R, H, D, J) and were affected by the duration of submergence. The particle and silt proportions in soil bulk density and its formation increased with increasing water levels. The soil total nitrogen level and community richness also indicated a positive relationship. In contrast, the diversity and dominance of plant communities showed a negative relation with TN and organic matter (OM). The OM content in soil decreased from 12.69 to 9.14 mg/kg initially and then increased to 14.78 mg/kg, showing a "V" type distribution. The total nitrogen content in soil increased linearly from 0.45 to 0.684 g/kg^-1. However, no obvious fluctuation was found in the available potassium (EP) content since it remained at 13.50 mg/kg, and the available phosphorus (AP) content decreased from 21.28 to 18.70 mg/kg and then remained unchanged. There was a positive correlation among the four diversity indices. Total nitrogen had a significantly positive relation with OM (R² = 0.533); OM had a negative correlation with EP (R² = -0.144), soil total nitrogen had a positive relationship with community richness, diversity, and dominance; available phosphorus had a positive relationship with the four diversity indices. The pH value had a negative relationship with the four diversity indices. The results of the regression analysis indicated that total nitrogen and OM are the key factors of vegetation diversity. Therefore, scientific vegetation management and comprehensive adjustment of nutrient salts are necessary to enhance the vegetation of the land/inland water ecotone.