Abstract: Considering the effect of the interface spin-flip scattering,the spin-injection across ferromagnet/nonmagnetic-semiconductor/ferromagnet heterostuctures with finite size was explored theoretically.Due to the fact that interfacial spin-flip scattering leads to spin-memory losses at the interfaces,the spin-up component of spin-polarized current could not be continuous across the interface.It is found that when the spin injection efficiency varies from zero to unity,the tunneling magnetoresistance of the ferromagnet/nonmagnetic-semiconductor/ferromagnet junction presents two orders of changes in magnitude,which reflects the fact that the spin-flip scattering at the interface directly affects the tunneling magnetoresistance of ferromagnet/nonmagnetic-semiconductor/ ferromagnet.