Abstract: A wooden screw may include a shank, a threaded segment, a screw head, a tapered portion and a stem portion. The shank diameter is smaller than the horizontal distance defined as a distance between two opposite ends of the tapered edges, while the width defined as a distance between two symmetric rear portions of blades is between the shank diameter and the horizontal distance, so a drill hole on the wooden material is not contacted with the shank during the screwing process, and the wooden screw also can reduce the friction and provide a complete mechanism for wood chips in accommodation and expulsion. Also, because the diameter of the drill hole is smaller than the horizontal distance, the tapered edges on the threaded segment are much easier to be screwed into wooden material. Therefore, the bonding strength between the wooden screw and the wooden material is increased.