An illuminant shoe has a body, an outsole and an illuminating device. The body has a putting segment, a lifting cover and an insole. The putting segment has a heel lining and a through hole. The lifting cover is connected to the heel lining. The insole is mounted in the putting segment. The outsole is mounted on the putting segment and has a mounting chamber. The illuminating device is mounted in the mounting chamber and has an illuminating module, a controlling module and a switch. The illuminating module has first wires, multiple illuminating elements and a first electrical element. The controlling module is connected to the illuminating module and has two second electrical elements, multiple second wires, a controlling unit, a battery and a protecting casing. The switch is mounted in the putting segment, is connected to the controlling module and has a third wire and a third electrical element.