A joint structure for a floorboard, including: at least one first beveled tenon, the first beveled tenon including a tenon face facing upwards; a first beveled mortise, the first beveled mortise including a mortise face facing upwards; at least one second beveled tenon, the second beveled tenon including a tenon face facing downwards; and a second beveled mortise, the second beveled mortise including a mortise face facing downwards. The first beveled tenon is disposed in parallel to a surface of the floorboard at a right edge approximately half a height of the floorboard; the first beveled mortise is disposed at an inner side of the first beveled tenon. The second beveled tenon is disposed at a left edge approximately half the height of the floorboard. The second beveled mortise is disposed at an inner side of the second beveled tenon.