Abstract: The spin-polarized transport properties of a quantum structure based on two anti-coupled T nanojunction with spin-orbit interaction have been studied.The spin polarization in the output lead as a function of the structural parameters has been calculated under two situations,of which one is spin-polarized injection,and the other is spin-unpolarized injection.It is found that very high spin polarization could be obtained under the appropriate structure when the injection is unpolarized.The physics underlying attributes to the difference transmission probabilities between the spin up and spin down electrons caused by the structure-induced electron wave interference.