Provided is a water absorption treatment material and a method for manufacturing the same, according to which separation of a coating layer portion is not likely to occur. A water absorption treatment material includes a granular core portion and a coating layer portion. A recessed portion is formed on the surface of the granular core portion. The recessed portion is intentionally formed on the surface of the granular core portion. The coating layer portion is provided so as to cover the surface of the granular core portion. A portion of the coating layer portion enter the recessed portion.