The present invention is a composition for coating comprising a wet-milled product obtained by suspending low-substituted cellulose ether having a molar substitution of from 0.05 to 1.0 per anhydrous glucose unit in water and then applying a shear force to the aqueous dispersion. The present invention is also a coated preparation prepared using the composition for coating so as to mask an unpleasant taste and to control a sticky or slimy feel by administration.