Described is a hydrophilic adhesive base material comprising a hydrophilic crosslinked polymer obtained by polymerizing (A) (a) a glucosyloxyalkyl (meth)acrylate, (b) an alkyl (meth)acrylate and/or a hydroxyalkyl (meth)acrylate and (c) a polyfunctional monomer; and (B) polyvinyl alcohol. The hydrophilic adhesive base material according to the present invention is free from lowering in the water content and has excellent mechanical strength and adhesion to the skin so that it is useful as adhesive layers in plasters, various medical pads and also medicament-impregnated dermatologic medicines.