Abstract: A run-flat core has a closed upper surface and an open lower surface and includes a reinforcement plate provided for reinforcement within the core. The core includes one or more blocks formed in the same shape with each other and connected in a circumferential direction of a wheel. The core has flanges protruding in right and left directions at a lower portion of the core. A band is wound onto the flanges, and by tensioning the band, the core is pressed to a rim. The blocks are connected to each other at a lower portion of the core. The core may include a longitudinal groove, and by winding the band onto the longitudinal groove, the core is pressed to the rim.