Disclosed herein is an overflow shutoff valve for a liquefied petroleum gas container. The overflow shutoff valve includes: a gas inlet mounted at the gas container; a safety valve protrudingly formed at one side of the upper portion of the gas inlet for discharging the internal pressure of the gas container when the internal pressure is rapidly increased; a gas outlet protrudingly formed at the other side of the upper portion of the gas inlet for supplying gas to a gas appliance; a valve handle for vertically controlling a valve stem mounted on a controlling part protruding from the upper portion of the gas inlet; a gas inflow and outflow hole located between the gas inlet and the controlling part for allowing inflow and outflow of the gas; a cylinder fit into the inner circumference of the gas inlet; and a ball positioned inside the cylinder, the cylinder and the ball being adapted to normally discharge the gas contained in the gas container and regulate a gas flow to prevent an excessive outflow of the gas, wherein the cylinder has an upper part, a lower part and an intermediate part between the upper and lower parts, each of which has the same thickness, and is made of a hollow pipe, the upper part having a plurality of upper incised slots of a uniform length vertically formed on the circumference thereof in an axial direction in such a manner as to be spaced apart from one another at regular intervals and be opened upwardly, and the lower part having a plurality of lower incised slots of a uniform length vertically formed on the circumference thereof in the axial direction in such a manner as to be spaced apart from one another at regular intervals and be opened downwardly.