An aqueous dispersion type pressure-sensitive adhesive composition which is excellent in adhesion to foams and unsusceptibility to edge peeling and retains stable adhesive force over long, a pressure-sensitive adhesive sheet including a substrate and, disposed on one or both sides thereof, a pressure-sensitive adhesive layer comprising the aqueous dispersion type pressure-sensitive adhesive composition, and a pressure-sensitive adhesive rubber foam sheet comprising a rubber foam and, disposed on one or both sides thereof, the pressure-sensitive adhesive layer or pressure-sensitive adhesive sheet. The aqueous dispersion type pressure-sensitive adhesive composition comprises an aqueous dispersion of a polymer obtained by copolymerizing a monomer mixture comprising one or more alkyl (meth)acrylates as the main component and at least one silane monomer, and a tackifier having a phenolic skeleton, added to the aqueous dispersion.