PURPOSE: Provided are a nursery system for raising fishes having buoyancy-control function and balance-floating function and a method of using the system. It is capable of floating on the surface of the sea and sinking to the certain depth of the sea. CONSTITUTION: The nursery system for raising fishes having buoyancy-control function and balance-floating function comprises the parts of: an outer frame(2) having sinking and floating function, manufactured by synthetic plastics, and forming an air valve; an inner frame equipped to the inside of the outer frame, equipped with a fish net, and forming an air valve at its upper part and a water outlet at its lower part; a plurality of balance-floats(4) with a water outlet at its lower part; a plurality of fish nets(17) with a weight frame; a fixing unit consisting of a plurality of floats(14,15) and supporting the system; and a control system.
