A run flat support body for a pneumatic tire, including an annular shell and elastic rings, where the elastic rings are composed of a composite elastic material made by compounding reinforcement fillers with an elastic material so as to provide anisotropy to an effect of reinforcement thereof. Additionally, the compressive rigidity of the elastic rings in a radial direction of the tire is made larger than that of unreinforced elastic rings in the radial direction, and the bending rigidity of the elastic rings in an axial direction of the tire is made substantially equal to that of the unreinforced elastic rings in the axial direction. Preferably, the elastic rings include a layered body formed by alternately laminating layers of a composite elastic material in which short fibers are aligned in a circumferential direction and layers of a composite elastic material in which short fibers are aligned in the axial direction.