Disclosed is an adhesive composition having adhesion properties, high-speed curing properties and moisture resistance. Also disclosed is an adhesion method. Specifically disclosed is a composition which comprises: a first preparation comprising (A) a nitrile-butadiene rubber, (B) a (meth)acrylic composition, (C) a compound having an enal structure, and (F) a radical polymerization initiator; and a second preparation comprising (A) the nitrile-butadiene rubber, (B) the (meth)acrylic composition, (D) a compound having an amine structure, and (E) a compound containing copper. Also disclosed is a composition which comprises: a first preparation comprising (A) a nitrile-butadiene rubber, (B) a (meth)acrylic composition, (D) a compound having an amine structure, and (F) a radical polymerization initiator; and a second preparation comprising (A) the nitrile-butadiene rubber, (B) the (meth)acrylic composition, (C) a compound having an enal structure, and (E) a compound containing copper.