Chinese sturgeon, Acipenser sinensis, is an endangered anadromous species that is currently only found in the Yangtze River and the coastal China Seas. It spawns in the upper Yangtze River in autumn every year. Juvenile fish make a downstream migration and reach the Yangtze Estuary during May and June of next year. All of juveniles leave the estuary for ocean during August to September. Yangtze Estuary is not only a passage route for both juveniles and adults migrating between freshwater and the ocean, but also an important feeding ground for juveniles. Because of overfishing and habitat alteration, the population of Chinese sturgeon has been rapidly declining during last decades. This species has been listed as the highest level of national protected wild animals by Chinese Government since 1980s. Understanding feeding habits and food competition of juvenile Chinese sturgeon with other fish species that inhabit in the Yangtze Estuary is very important for the conservation of this species. In this study, we compared feeding habitat and food competition between juvenile Chinese sturgeon and other 6 important fish species that widely inhabit in the Yangtze Estuary. Fish samples were obtained using tidal nets. During June and August of 2004 and 2005, tidal nets were set in the tidal flat of the Yangtze Estuary. Sample locations were 31°25.26′N, 121°54.38′E-31°32.57′N, 122°05.45′E, where are major habitats for juvenile Chinese sturgeon. Seven hundred and seven individuals of 7 fish species were collected, including Acipenser sinensis, Lateolabrax maculates, Liza haematochiela, Mygil cephalus, Coilia ectenes, Coilia mystus, and Cynoglissus gracilis. The alimentary canals of sample fish were taken out and preserved by quick-freezing. We weighed inclusions of the alimentary canals and indentified food items in laboratory. The study results indicated that the major food items of juvenile Acipenser sinensis are small fishes, amphipoda, polychaeta and crabs. Juvenile Acipenser sinensis and Cynoglissus gracilis feed on benthic organisms. Lateolabrax maculates mainly feeds on swimming animals, including fishes, shrimps, isopoda and crabs. Coilia ectenes and Coilia mystus feed on zooplanktons. Liza haematochiela and Mygil cephalus mainly feed on organic scraps and benthic algae. The decreasing order of the index of relative importance (IRI) of juvenile Acipenser sinensis is fishes > amphipoda > polychaetes > crabs, that of Cynoglissus gracilis is shrimps > lamellibranchiata > fishes, that of Lateolabrax maculatesb is fishes > shrimps > isopoda > crabs, that of Coilia ectenes is shrimp bran > shrimps > copepod > fishes, that of Coilia mystus is shrimp bran > copepod > shrmps > fishes, and that of Mygil cephalus and Liza haematochiela is organic detritus > benthic algae > lamellibranchiata > copepod. The food overlap coefficient (Ojk) of juvenile Acipenser sinensis and other 6 species were analyzed and the results showed that Ojk between juvenile Acipenser sinensis and Cynoglissus gracilis is 0.4, and Ojk between juvenile Acipenser sinensis and the rest of other 5 species are less than 0.12, respectively. Therefore, it may be inferred that the food competition between juvenile Acipenser sinensis and Cynoglissus gracilis is high, and the food competition between juvenile Acipenser sinensis and the rest of other 5 fish species is low. In conclusion, the feeding habits between juvenile Acipenser sinensis and the most of other 6 fish species those are dominant species in the Yangtze Estuary are mainly different, thus, food competition between them are generally low. Moreover, abundant food may be provided for juvenile Acipenser sinensis in the Yangtze Estuarine area. Yangtze Estuary is a very important and suitable feeding ground for juvenile Acipenser sinensis.