PURPOSE: To provide a high stability ship with large stability at the turning time so as to have little possibility of overturning and that able to make a sharp turn.

CONSTITUTION: A high stability ship has a hull 1, floats 2 disposed at both sides of the hull 1, a connecting means 3 for connecting these floats 2 to the hull 1, and deck arms 4 fitted to the hull 1 in such a way as to protrude to the upper side of the floats 2 so as to press down the floats 2 into the water by the tip parts coming in contact with th floats 2 by the lateral inclination of the hull 2. The connecting means 3 is formed by holding bar members 32 of such shape as to surround the hull 1 in plane shape, oscillatingly in the lateral direction by supporting bodies 31 protrusively formed at the hull 1, at the bow end and stern end. The floats 2 are fitted to these bar members 32.