A foldable stool has a stool surface and two support legs; the stool surface is made of flexible materials capable of being folded to form a storage compartment; two support legs are swingly connected to each other, the top of two support legs are respectively connected to the left side and right side of a bottom surface of the stool surface; each support leg is hollow inside with an upper section, a middle section and a lower section connected together; an elastic rope runs through inside of each support leg, when the elastic rope is extended, the three sections are separated from each other and rotatably folded into the storage compartment. The stool is simple in structure, light and easy to use and low in cost, easy to carry and also is very beautiful.