We have investigated the magnetoresistive properties of CoxFe1-x/Cu multilayers with different CoxFe1-x and Cu thicknesses, prepared on MgO(110) substrates using ion beam sputtering. The MR ratio for Co9Fe/Cu multilayers was significantly larger than that for Co/Cu multilayers. The MR ratio oscillates for Cu layer thickness with a 12 Å period for all the multilayers investigated. The Cu intervening magnetic layer coupling depends on the Co concentration and has a broad maximum around x = 0.8. The uniaxial anisotropy induced by epitaxial growth in the multilayers on MgO(110) substrates led to a low saturation field and quite a small field change ΔH needed for giant magnetoresistance. An MR ratio of 16% was attained for ΔH = 50 Oe at room temperature.