Abstract: The paper elaborates on the characteristics of the transmission coefficient and the shot noise of a ferromagnetic/semiconductor/ferromagnetic heterojunction with double δ tunnel barrier in the existing external magnetic field.The effects of the quantum size and Rashba spin-orbit coupling are discussed.The results show that the transmission coefficient and the shot noise continuously oscillate as the length of the semi-conductor changes when the spin-dependent electron tunnels through the hetero-junction.The frequency of the transmission coefficient and the shot noise increase as the Rashba spin-orbit coupling and the external magnetic increase.The frequency of the shot noise will change as the angle of the external magnetic changes.The existence of the double δ tunnel barrier increases the swing of the transmission coefficient of the spin-electron

Key words: double tunnel barrier, ferromagnetic/semiconductor/ferromagnetic heterojunction, Rashba spin-orbit coupling, transmission coefficient, shot noise