Fe/Cr,Fe/Cr/Si and Fe/Si multilayered systems were prepared by the vacuum evaporating method. The effects of the altered space thicknesses of the nonmagnetic Cr,Si and Cr+Si layers on the exchange coupling and the magneto resistance of those multilayers were studied. The Fe layers were fixed on 2.0nm. The oscillation of the interlayer coupling and the giant magnetoresistance (GMR) and its oscillation with the change of the Cr layer thickness were observed. The GMR was 14.6% at 4.2K. Three was no oscillatory effect of the exchange coupling and GMR in the Fe/Si and Fe/Cr/Si multilayers was found. According to the increases of the resistivity of the samples doped with Si layers, we believe the conducting electrons in the nonmagnetic layers should decrease largely. This would be the cause to reduce the polarization effect of those electrons in the space layers. Then the oscillatory exchange coupling disappeared and the magnetoresistance was much reduced.