Abstract: An improved screw structure to be used exclusively for the wood plate mainly comprises of a smooth shank on the upper end portion of the screw body, the round thread teeth on the intermediate section and the helical thread teeth in tetragonal shapes on the lower end portion, wherein the pointed portions of the tetragonal thread teeth are arranged at different angles for cutting the wooden materials being drilled; furthermore, since the tetragonal shapes of the thread teeth reduce the frictional force occurred during the screwing process, the operation becomes more labor saving, works fast and prevents the wooden materials from being cracked.