PURPOSE: To let each life preserver be housed in a compact state as well as to let it be quickly expanded and developed at time in use so as to let both specified buoyancy and circumferential length be secured.

CONSTITUTION: A gas cylinder 7 is connected to one end of each resin hose buoyant body 6 which is roughly in a flat shape when no gas is filled in, and can be folded or wound up, and the other end of the cylinder is blocked. And the resin hose buoyant bodies 6 are folded in a state that they are connected to each other, so as to be housed in a container 2. In the case of a disaster and the like, gas is filled into the resin hose buoyant bodies 6 out of the cylinder 7, the bodies are expanded so as to be developed, so that specified buoyancy is thereby produced. By this constitution, the specified buoyant bodies can be housed in container in a compact state, and they can be quickly expanded so as to be developed in a specified shape in the case of a disaster, so that both specified buoyancy and circumferential length can thereby be secured.