There is provided a modified two-part type adhesive composition comprising liquid I composed of an acrylic monomer, an organic peroxide, and, if necessary, a gelation stabilizer and liquid II composed of an acrylic monomer, a curing accelerator, and, if necessary, a gelation stabilizer, at least one of the liquids containing a modified nitrile rubber in an amount of 2 to 50% by weight, and said modified nitrile rubber having carboxyl groups and the carboxyl groups being bonded to a (meth)acrylic group-containing acid phosphate through partially a covalent bond and partially an ionic bond.