To provide a method for growing a deep-sea creature, inexpensively and precisely applicable to the deep-sea creature without requiring a high-pressure device or the like in a growing method for enabling the deep-sea creature to adapt to a normal pressure environmental condition on the ground; and to provide a system for growing the deep-sea creature therefor.

The method for growing the deep-sea creature in the normal pressure condition involves enabling the deep-sea creature to be adapted to the normal pressure environment in seawater by gradually changing the hydraulic pressure from a pressure state of ≤10 atm, to the normal pressure. The system for growing the deep-sea creature has a growing aquarium for growing the deep-sea creature and filled with the pressurized sea water, a pressurizing means for pressurizing the sea water in the growing aquarium by water depth pressure, a cleaning device for cleaning the sea water in the growing aquarium, a temperature regulator for regulating the temperature of the sea water in the growing aquarium, and a circulating means for circulating the sea water in the growing aquarium.