To explore the species diversity of freshwater fishes and its position in zoogeographical regionalization, this study conducted field investigation on 132 river sections of the lower reaches of the Yangtze River, Poyang Lake, Qiantang River, Oujiang River, Minjiang River and Hanjiang River system, and collected more than 13000 fish specimen for the comprehensive analysis. There were 255 species of pure freshwater fishes naturally distributed in the central and southern mountainous areas of East China, belonging to 5 orders, 22 families and 99 genera. Among them, there were 182 species of Cypriniformes, 40 species of Perciformes, 27 species of Siluriformes, 4 species of Synbranchiformes and 2 species of Cyprinodontiformes with 58 endemic species mainly found in southern river systems, such as Hanjiang (20 species), Minjiang (20 species) and Oujiang (16 species), of which Cyprinidae, Gobiidae and Gastromyzontidae were accounted for 33.7%, 28.8%, and 28.8%, respectively. The average similarities of species among the 6 river systems were from 50.8% to79.8%. Almost all species of the genus Pseudogastromyzon
were concentrated in the region. Fauna analysis showed that the proportion of East Asian River Plain fishes gradually decreased from 50.0% in the northern river systems to 40.0% in the southern river systems, and the proportion of South Asian warm-water fishes decreased from 32.5% in the southern river systems to 15.6% in the northern river systems. These results indicate that the Nanling-Wuyishan-Donggong mountains are the boundary of the South China Area and the East China Area in the South-east Asiatic Subregion, and the Minjiang and Hanjiang river systems in the south belong to the South China Area, and that the river system of Fujian and southern Guangdong, including the Minjiang River and the Hanjiang River, can be named the Minyue Subarea of the South China Area, the river system from the Oujiang River, Qiantang River to the lower reaches of the Yangtze River can be named the Zhejiang-Jiangsu-Anhui Subarea of the East China Area, and the Poyang Lake water system is part of the Ganxiang Subarea of the East China Area.