A record body size, length of 1520 mm and weight of 12,600 g for the beach conger, Conger japonicus was recorded, which is approximately 120 mm and 2600 g larger than the previous international record. The specimen was female and obtained during an otter trawl survey on 4 April 2013 in the East China Sea (31°52.16′N 127°42.94′E) at a depth of approximately 140 m on the slope of the continental shelf. Morphometric measurements and meristic counts are reported in this paper. We also report profiles of water temperature, salinity, dissolved oxygen and chlorophyll-a taken immediately prior to the trawl, and species composition of concurrent catch with the otter trawling as environmental and biological characteristics of the habitat.