CAP SEALING STRUCTURE

To provide a cap sealing structure capable of improving sealability between a container and a cap and sealability between a spouting cylinder of a cap body and a sealing cylinder even if resistance is reduced when the cap is fitted to the mouth of the container.SOLUTION: This sealing structure for a cap fitted to the mouth 1 of a container A is constructed such that the cap comprises a fitting part 5 fitted to the mouth 1 of the container A, and a wall extended inward from the fitting part 5 to close the container, and the fitting part 5 comprises an inner cylinder 12 for sealing the inner periphery of the mouth 1 of the container A, a main seal 15 formed in the outer periphery of the inner cylinder 12 to be pressed into contact with the surface thereof, and auxiliary seals 16, 17 formed below the main...