In a connection structural body, an aluminum electric wire tip part and a crimp terminal are connected to each other. The aluminum electric wire tip part is an exposed tip part of an insulated wire including an aluminum core wire and an insulating cover for covering the aluminum core wire. The crimp terminal includes a wire barrel section for pressure-bonding and thus connecting the aluminum electric wire tip part and is formed of a metal material having a higher potential than that of the aluminum core wire. The aluminum electric wire tip part is covered with a cover solder and/or a cover resin, pressure-bonded, and connected to the wire barrel section such that the aluminum electric wire tip part is covered with the cover and/or the cover resins, with no gap, from an insulating cover tip part to a rear end portion of the wire barrel section.