The selection and application of ornamental plants are the keys to constructing urban green infrastructure. It is also an important content of building a beautiful countryside and ecological city in Shanghai. Based on the investigation of the application status of greening plants, the species composition, life form, species composition, and local species proportion of plants were analyzed in Changxing Island, Shanghai. The results indicated that there are 283 species of vascular plants belonging to 211 genera, 88 families, with more species composition of single species and few species. There are 153 woody plant species, accounting for 54.1% of the total. There are 26 native tree species, accounting for only 17.0%. Combined with the regional development objectives and the current situation of plant application, the planning, development objectives, and recommended species of suitable plants provide a rich basis for greening plant resources for the construction and development of the ecological island.