A new-type tire is presented, in which there is no air leakage when nails break the tire. The broken part is repaired automatically by its self-repairing mechanism. The self-repairing sealant layer is consisting of two rubber sheets with lattices inside. Polymer particles are inserted in the lattices in the sealant. Coolant fluid diluted with water is inserted in the polymers umiformly, and so the polymer particles expand with water diluted coolant fluid, and become gel. Hence, they stop air leakages in the tire. The sealant is pasted to the inside wall of the tire. A method of making the sealant is developed, and vibration characteristics of the tire with the sealant are investigated.