Fish fauna in Northeastern Jiangxi province is composed of 135 species or subspecies, among which 128 or 94.8% are freshwater species, 80 or 62.5% are cyprinids which are the dominant group. The species in the fish fauna are mostly endemic in river plains in East Asia, such as Xenocyprinae, Cultrinae, Hypophthalmichthyinae, Gobiobotinae, Acheilognathinae and some genera of Leuciscinae and Gobioninae of Cyprinidae. The fauna is similar to the fauna in Qiangtangjiang and Xiangjiang Rivers, but differs from the fish fauna in the Mingjiang River. The fish fauna in Northeastern Jiangxi province, in southern part of Anhui province and in the Tianmu mountain area in Zhejiang province represent the most northern geographical distribution of Homalopteridae, Sisoridae and Labeoninae of Cyprinidae in East China. The formation and evolution of fish fauna in Northeastern Jiangxi province bear a great significance with the historical event in geology. The global temperature decrease in the middle stage of the Tertiary period resulted in the extinction of more primitive groups such as barbine and danionine fishes which might previously have occurred in this area, although a few widespread species, such as Zacco platypus remains. The uplift of Qinghai-Xizang Plateau caused the erection of the rapid current water environment around its adjacent area; consequently, the torrential water fishes in the Oriental Region arose in South Asia. Following the establishment of the monsoon climate which resulted from the uplift of Qinghai-Xizang Plateau, the endemic fishes of the river plain in East Asia originated during the late stage of the Tertiary Period, and become the major component of the fish fauna in Northeastern Jiangxi province. Moreover, the neotectonic movement and the glacial period climate during the Quaternary period made it possible to occur that the torrential water fishes in Oriental Region might have dispersed eastwards or northwards. Meanwhile, Phoxinus oxcephalus might have emigrated southwards. As a result these fishes occur in Northeastern Jiangxi province. With regard to zoogeographical division of Eastern China, it is suggested that the middle and lower Yangtze river district including Northeastern Jiangxi province should located in the Oriental Region; Wuyi Mountain Rang, Tiantai Mountain Rang and Xiangxialing Mountain Rang should serve as a zoogeographical boundary line on a relative lower level in the South-east Asiatic subregion; Dongting lake system and Poyang lake system should share with Qiangtongjiang river system the same level in zoogegraphical division.