The East China Sea is one of the best fishing grounds in the world based on high productivity and has been utilized cooperatively by the surrounding countries. The fisheries resources are, however, decreasing and an effective resource management strategy is required. However, the species composition of the catch and discards of the by-catch from the bottom trawl fishery in the East China Sea have not yet been fully understood. For sustainable utilization of the demersal resources, the experiments with a bottom trawl were carried out to investigate this quantitatively. Forty one experimental trawling with the gear were carried out in the East China Sea aboard the training vessel Koyo-maru in every April from 1997 to 2003. A total of 30,425 individuals composed of 180 species were caught during the research period. The numerically dominant species were Trachurus japonicus (7,800individuals, 25.6%), Photololigo edulis (4,017individuals, 13.2%), Argyrosomus argentatus (2,470individuals, 8.1%). Of the total catch in number, the discards accounted for 20.4%. The main discarded species with no commercial values were Acanthocepola krusensterni and Macrorhamphosus scolopax, while those with commercial value was a swimming crab (Ovalipes punctatus), which is a target fish of bottom trawl fishery in the East China Sea. To manage resources and promote a sustainable fishery in the fishing grounds, Japan and surrounding countries should create opportunities of discussing the survey fishing gear and techniques and for conducting surveys to assess catches accurately.