Abstract: The invention publics a lock of box/bag, the lock of box/bag is convexly set on the box/bag body, it comprises a lock bolt which is fixed to one side of the box or the bag; a lock body, the lock body comprises a fixed part and a rotating part, the fixed part is fixed to the other side of the box or the bag, the rotating part is pivotally connected to the fixed part, and the rotating part is provided with an opening, and extending inwardly along the opening an sliding groove is provided, which is to allow the lock bolt to slide therein so as to lock or unlock. The lock of box/bag of the invention is locked and unlocked by rotating, which is different from current snap lock, it is a new lock of box/bag, and it is provided with a lock core that make it is need to use a key to open it, and improve its safety greatly; the shape of the lock is preferably circular, of which the advantage is easy to operate.