There are provided a coating composition for applying inkjet printing thereto to form a marked preparation, the composition providing good ink affinity, suppression of ink bleed, and excellent gloss; and others. More specifically, there are provided a composition for applying inkjet printing thereto to form a marked preparation, the composition including a water-soluble cellulose ether having a viscosity at 20° C. of from 2 to 50.0 mPa·s, as determined in 2% by mass aqueous solution, polyvinyl alcohol, and a solvent, wherein a mass ratio of the water-soluble cellulose ether to the polyvinyl alcohol is from 99.0:1.0 to 55.0:45.0; a method for producing a preparation marked with aqueous ink, including a coating step of coating an object with the composition to form a coating layer, and a printing step of inkjet-printing on the coating layer with aqueous ink to obtain a preparation marked with aqueous ink; and others.