To provide a seawater circulation apparatus which is capable of taking in seawater effectively.

The seawater circulation apparatus 1 introduces seawater W near the sea surface S into the sea bottom B and is provided with a floating water tank part 2 in which a seawater intake opening 21 is formed at the position protruding from the sea surface, and in which an exhaust opening 23 is formed at the bottom face, an aqueduct 3 whose upper end is connected to the exhaust opening and which extends near to the sea bottom, a resistance body 4 which projects toward the side part of the aqueduct, and a water drain pipe 5 which extends from the lower end of the aqueduct and in which discharge openings 51 and 52 are formed.