Species replacement has a potential impact on the soil geochemical cycle in the process of vegetation restoration in the hydro-fluctuation zone of the Three Gorges Reservoir. In this study, the rhizosphere and bulk soils of Cynodon dactylon, Hemarthria altissima, Taxodium distichum, and Salix matsudana were collected between 165-170 m elevation in the vegetation restoration demonstration base of Ruxi River to clarify the growth adaptability and nutritional utilization strategies of these four suitable plant species within a more precise rhizosphere range. We would like to compare soil amelioration effect by exploring the differences of nutrient contents and enzyme activities between rhizosphere and bulk soils. The results showed that:(1) root activities of four suitable plant species in the hydro-fluctuation zone of the Three Gorges Reservoir resulted in differences in soil nutrient contents and soil enzyme activities between rhizosphere and bulk soils. The soil nutrient conditions were improved to a certain extent by planting. (2) Carbon and nitrogen were enriched in different degrees in rhizosphere soils, but the changes of phosphorus and potassium in rhizosphere and bulk soils of different species were not consistent. (3) Sucrase, urease and acid phosphatase showed different degrees of positive rhizosphere effect (R/S>1) in four suitable plants, and C. dactylon had the most obvious activation effects on three soil enzymes in the rhizosphere, with the values of rhizosphere effect were as high as 2.39, 1.89 and 2.7, respectively. (4) The correlation between organic matter, nitrogen, phosphorus and potassium was more significant with the regulation of plant roots in the rhizosphere, however, only potassium had negative correlation with available nitrogen and phosphorus significantly. There was no significant correlation among other soil nutrient factors in the bulk soil. (5) Compared with T. distichum and S. matsudana, C. dactylon and H. altissima had more reasonable nutrient regulation patterns in rhizosphere and had better effects on soil improvement in the reservoir.