Influences of Ti seed layer on the structural and magnetic properties of Co/Cu multilayers with varying Ti seed layer thickness have been studied. The results of X-ray diffraction proved that by depositing thin Ti seed layer, the crystal orientation of Co/Cu multilayer was controlled to face-centered cubic (001) orientation, and changed to (111) orientation when the thickness of Ti layer was greater than about 4 nm. The maximum value of magnetoresistance ratio was enhanced with increasing the thickness of Ti seed layer, regardless of the orientation change of the multilayer, and it was found that the shunting effect as well as crystal orientation and interface sharpness was important for further enhancement of the giant magnetoresistance effect. (c) 2006 Elsevier B.V. All rights reserved.