Abstract: A water-disintegrable sheet having biodegradability. The sheet comprises one or more kinds of biodegradable synthetic fibers, and one or more kinds of natural fibers and/or regenerated fibers, all the fibers being bound together by a binder such that the binding power of the binder will be substantially lost in water. The sheet has a given degree of tensile strength and good softness, coupled with a required degree of liquid absorbency, and still has some biodegradation property. Therefore, the sheet can be flushed in a flush toilet without involving any appreciable increase in the volume of solid residues in a septic tank and/or in a sewage disposal plant and is therefore suitable for use in the form of a wet wiper in particular.