Abstract: Cu/Co nanomultilayers were prepared by electrocrystallization in boric acid solution.By the cyclic voltammetry,the deposition and dissolving potential of Cu and Co have been determined.Cu deposition starts at-0.55V（vs.SCE）and Co deposition starts at-1.05V（vs.SCE）.The structure and composition of the deposited multilayers were studied by the XRD and XRF.The PPMS was used to characterize magnetic properties of the electrodeposited multilayers.The results show that coercivity of the multilayers is only 34 Oe.The GMR value decreases when the magnetic intensity increases,and keeps steady when the magnetic intensity is about 3000 Oe.The GMR is up to 14 %.