Abstract: A cover structure of a cup (bottle) is disclosed. The cup (bottle) has an accommodating space therein for containing a liquid. An upper end of the cup (bottle) has an opening. The cover structure includes a cover body and a liquid discharge mechanism. The cover body has a first plane for closing the opening, a wall portion extending upward from the first plane by a predetermined height, and a second plane extending horizontally from an upper edge of the wall portion and parallel to the first plane. The liquid discharge mechanism includes a guide tube insertedly disposed on the first plane for guiding the liquid in the cup (bottle) and a switch disposed on the guide tube. The guide tube has an outlet end extending out of the wall portion. When the cup (bottle) is inverted, the liquid in the cup (bottle) is discharged through the guide tube for drinking.