This invention provides a water-dispersed PSA composition comprising an aqueous solvent, an emulsifier and polymer particles. The polymer particles comprises a particle that has a core-shell structure and comprises an acrylic polymer at least in either its core or shell while the glass transition temperature of the core-constituting polymer is higher than the glass transition temperature of the shell-constituting polymer. The emulsifier content in the PSA composition is lower than 3.5 parts by weight relative to 100 parts by weight of the polymer particles. The average particle diameter of the PSA is smaller than 0.3 µm when measured by a laser diffraction/scattering method.
