Magnetization reversal of Co/Pd nanomultilayers was contrastingly changed from wall-motion dominant to nucleation dominant with varying multilayered structure. Quantitative analysis revealed that the reversal behavior was ascribed to sensitive change in the wall-motion speed. The reversal behavior was well explained by Neel-Brown model and activation volumes of the wall motion and the nucleation processes were found to be the same. (C) 2000 Elsevier Science B.V. All rights reserved.