To provide a lightweight connecting structural body capable of easily connecting a concrete structural body within a short period of time, a bolt used for the connecting structural body, and provide a connecting method for the same.

After a hole made in a connecting plate 30 formed of a plastic material has been fitted to a nut position fixed to each concrete structural body in a state to fit an alignment face of the concrete structural body, the concrete structural body is connected by driving the driving fit bolt 20 forming a projection locked to a thread groove of the nut.