The fish composition of intertidal creek of Jiuduansha wetland in the Yangtze River estuary has the typical ichthyofauna trait of Yangtze River estuary. To comprehend the fish species composition and diversity of this wetland especially the intertidal creek, we surveyed the creek of Shangsha, Zhongsha and Xiasha five times from 2009 to 2010. A total of 3 637 tails with 105 158.9 g and 42 species were captured, these species belonging to 11 orders and 22 families. The fishes number and species number of Perciformes are the highest, with 20 species, 3 433 tails, next, Cypriniformes and Clupeiformes with 7 species,49 tails and 5 species,33 tails respectively. The percentage of marine species is 26.19%, estuarine species is 40.48%, freshwater species is 23.81% and diadromous species is 9.52%. The number of fishes(94.4%) and wet weight(96.3%) of estuarine species both were absolutely dominant. The catch in Shangsha, Zhongsha and Xiasha were 21 species with 742 tails 51 025.2 g, 30 species with 1 007 tails 29 427.5 g and 20 species with 1 888 species 24 696.2 g respectively. Most of them were estuarine species. According to the relative density(RD) and relative significance index(IRI), it shows that Acanthogobius ommaturus, Liza haermatochiel and Eleutheronema tetradactylu were dominant species, especially the Acanthogobius ommaturus has the absolute advantage. As for diversity, the diversity in Shangsha is lower than the Jiuduansha wetland overall level. There are relatively fewer fish species here.