A battery box structure includes an enclosure which defines a first receiving groove, a first circuit board, a push button elastically disposed between the enclosure and the first circuit board, and a battery holder. At least one pair of conductive terminals is fastened to the first circuit board. A tail end of each of the conductive terminals is arched downward to form a resilient contact portion. The battery holder includes at least one pair of conductive pads. A bottom end of the push button is buckled with a top end of the battery holder. The battery holder is assembled in the first receiving groove. Each of the conductive pads electrically contacts the resilient contact portion. When the push button is pressed rearward, the bottom end of the push button breaks away from the top end of the battery holder. The battery holder is automatically ejected out of the enclosure.