The present invention provides an adhesive sheet which does not change into a grapefruit skin, is excellent in weather resistance, foam resistance, and removability and does not cause a zipper sound phenomenon. The invention also provides an adhesive composition via which the adhesive sheet can be obtained. The adhesive composition of the present invention is an adhesive composition comprising a (meth)acrylic copolymer (A), a (meth)acrylic copolymer (B), and a crosslinking agent (C), The acrylic copolymer (A) is an alkyl (meth)acrylate containing a homopolymer having a Tg of 0 DEG C or higher,a homopolymer having a Tg of less than 0 DEG C and containing a copolymer of a monomer component of a monomer of a carboxyl group; the above (meth)acrylic copolymer (B) is a copolymer of a monomer component comprising an alkyl methacrylate and an amino group-containing monomer; the polymerization initiation amount contained in 100% by weight of the solid content of the object is 800 ppm or less.