Provided is a colon delivery system which enables the delivery of an active ingredient to the large intestine without losing the active ingredient in the stomach or the small intestine and can release the active ingredient in the large intestine rapidly. A colon delivery composition comprising a capsule that encapsulates a bacterium useful for the large intestine, alginic acid and a calcium salt therein, a chitosan-containing layer that covers the capsule, and an enteric-base-material-containing layer (i.e., a layer containing an enteric base material) that covers the chitosan-containing layer, wherein the mass of chitosan in the chitosan-containing layer is 0.5 to 8.0 mass% relative to the mass of the capsule.
