Abstract: Based on the historical data on the composition of fish species in coral reefs from Dongsha Islands, South China Sea, the recorded fish species composition was updated, and the average taxonomic distinctness △+ and variation in taxonomic distinctness + were tested. The result indicated that a total of 403 species were devided into 173 genera, 68 families and 18 orders, while Perciforms dominated in species abundance. The mean △+ was about 55.2, lower than that in Huanghai and Bohai seas, the Yangtze River Estuary and the East China Sea Continental Shelf (P0.01). The mean + was about 110, also lower than that in these areas. However, there was no significant differences between Dongsha Islands and East China Sea Continent Shelf (P0.05). The △+ of marine fishes generally displayed a positive relationship with latitude on a large scale, deemed that the relationship among fish species in Dongsha area was more closely related than continental shelf and estuary area.