There is disclosed a sealing material for sealing a ceramic structure, the sealing material containing a ceramic component, an ordinary-temperature liquid component, and a suspending agent. In a method in which opening end portions of a large number of through channels 3 divided by partition walls 2 and extending in an axial direction in a honeycomb structure 1 including the through channels, the method comprises the steps of: sealing the opening end portions using the above-described sealing material. Sealed portions 10 are formed in the opening end portions of the through channels 3 by the sealing material. There are disclosed a sealing material, a sealing method for a honeycomb structure, and a sealed honeycomb structure in which less kinks are generated in the sealed portions, and a depth in each sealed portion fluctuates little.