Herein provided is a method for easily preparing a sustained release tablet which contains an orally administrable medicinal component, while maintaining the uniformity of the content of the medicinal component. The method comprises mixing (1) a granulated product A obtained by granulating an excipient and an enteric coating agent while spraying thereon with a solution or a suspension containing an orally administrable medicinal component, with (2) a composition B containing a hydrogel-forming substance and then compressing the resulting mixture into a tablet.
