To provide a clamp for fastening a wood joint, which enhances the strength of a wooden structure by causing a tightening force to act on the mating surfaces of wooden columns to bring the wooden columns closer together through the driving of the clamp so that wooden members are firmly joined together.

The clamp for clamping and driving into the mating surfaces of wooden members has opposite leg parts 2 formed at both ends of a horizontal part 1 and perpendicularly to the horizontal part. The ends of the leg parts 2 are sharply pointed so as to be driven into the wooden members. Inclined faces 3 that slope down from the ends toward the center of the horizontal part 1 are formed on the opposite sides of the leg parts 2.