In a connecting structure of a terminal configured to connect a female terminal inserted into a terminal accommodating chamber to the male terminal, the female terminal comprises a tubular part made of a metal plate and formed into which the male terminal is inserted, a plate shaped engaging piece continued from a side wall of the tubular part and folded back so that the engaging piece is located in a path into which the male terminal is inserted, a notch formed on an outer side surface of a folded back part of the engaging piece. The male terminal is provided with a cut-out part which can accommodate the engaging piece, and the engaging piece is accommodated in the cut-out part when the female terminal is inserted to a set position to lock a movement of the female terminal in a pulling out direction.