Abstract: In order to screen and rationally allocate pioneer plants suitable for vegetation restoration in the riparian zone of the lower reaches of the Yangtze River, the dominant herbaceous plants (importance values greater than 1% and ranking in the top 20) in the riparian zone of the Nanjing section of the Yangtze River were used for this study. Niche measurement, variance ratio (VR), χ2 test, association coefficient (AC), Pearson's correlation test, Spearman's rank correlation test and M. Gordon's stability analysis were employed to analyze the niche and interspecific relationships among 20 species, and ecological species groups were classified. The results showed that: (1) A total of 179 species of plants belonging to 36 families and 113 genera were recorded, among which Artemisia caruifolia, Phragmites australis, Leonurus japonicus, Phalaris arundinacea, Cnidium monnieri, Potentilla supina, Hemisteptia lyrate and Rumex dentatus had larger importance values and niche widths, holding the absolute advantage. (2) The ecotope overlap and similarity among dominant plants were in a moderate degree, with mean values of 0.54 and 0.48, respectively. (3) The overall dominant plants were significantly positively linked. The community stability analysis results showed that the community was currently in an unstable state. In addition, four tests (χ2, AC, Pearson and Spearman) all showed that the positive and negative association (correlation) ratios between dominant species pairs were greater than 1, and the number of non-significantly associated pairs accounted for the majority of the species. In summary, the dominant herbaceous plant communities in the riparian zone of the Nanjing section of the Yangtze River were generally in a dynamic process of positive succession, and the interspecific relationships were loose, with most species tending to share the environmental resources in the riparian zone. In conclusion, the above eight dominant herbaceous plant species were recommended as the pioneer species. According to the divided ecological species group, the simulation of configuration test was suggested to carry out along the corresponding riparian zone space, so as to construct a stable suitable plant community in the riparian zone.