Abstract: Based on field surveys and specimen identification, we analyzed the species composition and geographical distribution of seed plants from five uninhabited islands in Pingtan, Fujian. We compared the distribution patterns of seed plant genera from these islands with those from different regions and explored the species similarity among the five uninhabited islands, as well as the relationship with spatial characteristics of the islands. Results showed the following: (1) The five uninhabited islands contained 213 species of seed plants from 71 families and 179 genera (including infraspecific units). After excluding 42 exotic species, 171 native species from 65 families and 145 genera remained, with herbaceous species comprising the largest proportion, followed by shrubs, lianas, and trees. (2) At the family, genus, and species levels, the prominent distribution types were pan-tropical and its variants, with tropical and subtropical components being the most represented. (3) Flora showed a tropical to temperate zone transition with increasing latitude, reflecting the latitudinal divergence in the geographical components of the island flora. (4) In terms of genus similarity, plant species similarity among the five uninhabited islands was generally low. In addition, spatial parameters, such as shoreline length, elevation, and perimeter/area ratio, also influenced species richness of the islands to some extent.