To provide a water dispersion type acrylic pressure-sensitive adhesive which is a pressure-sensitive adhesive composition highly satisfying both of low temperature pressure-sensitive adhesion and curved surface adhesion and excellent in storage stability, and to provide a pressure-sensitive adhesive sheet using the same.

There are provided a water dispersion type pressure-sensitive adhesive composition comprising a water dispersion of an acrylic copolymer having a -75°C to -30°C glass transition temperature and a water dispersion of a polybutene having 800-2,000 number average molecular weight, wherein the content of the polybutene to 100 pts.mass acrylic copolymer is 1-50 pts.mass, and a pressure-sensitive adhesive sheet provided by coating the pressure-sensitive adhesive composition on one or both surfaces of a substrate and drying. Further, the pressure-sensitive adhesive sheet preferably has ≥1.0 N/10 mm pressure-sensitive adhesion measured according to JIS Z 0237 in -15°C circumstance by using a polypropylene plate as the adherend and/or ≤10 mm peeled distance of the test piece end part in the curved surface adhesion test.