Provided is a water-disintegrable sheet obtained by impregnating a base sheet with an aqueous chemical agent, wherein the base sheet has a per-unit area weight of 30-150 gsm and contains a water-soluble binder and cellulose nanofibers, the aqueous chemical agent contains a cross-linker for cross-linking with the water-soluble binder, the base sheet is in the state where the contained amount of thewater-soluble binder and the cellulose nanofibers gradually increases from the inside to the outside of the base sheet in the thickness direction, and when an abrasion resistance test is carried outthree times each in the MD direction and the CD direction by an oscillation-type rubbing fastness tester in which a PP band is used as an oscillator, calculation of the average of three measurements for each direction results in an average value of not less than 40 times for each direction. Thus, the resistance to breakage under intense abrasion is improved while water-disintegrating ability is ensured.