To provide a circulation/filtration device for culturing water of fishes, without having unbalance in the flow of the culturing water within a filtering material, capable of extending the staying time of the culturing water within the filtering material in the filtration device of the culturing water of the fishes, exhibiting a good filtration efficiency and capable of performing a high degree filtration treatment.

This circulation/filtration device for culturing water of the fishes is provided by installing a pump (1) for pumping up the culturing water at one end of a pipe, connecting a culturing water inlet port (2) and filtration vessel parts (3) with the pipe, installing a net state filtering material-supporting plate (8) at the upper and lower ends of inside of the filtration vessel part (3) and filling a filtering material (9). Each of the filtration vessel parts (3) is constituted so as to be connected with a lower precipitation vessel part (4) through an upper filtration vessel-connecting part (9) in a coil shape. A treated water outlet port (7) is installed at the one end of the rearest part of the filtration vessel part (3). At the one end of each of the precipitation vessels, a sludge-discharging port (5) and a sludge-discharging valve (6) are installed.