We report here the magnetization reversal study of dipolar coupled Ising-like dot array, where nanodot arrays of Co/Pt multilayer with perpendicular magnetic anisotropy are patterned in a self-assembled way based on a colloidal lithography. To investigate real magnetization reversal behavior of dot arrays, we have taken an AFM image of a dot array to obtain quantitative topological information of dot array and carried out micromagnetic simulation over the area considering the topological profile obtained from the AFM image. We find that there exists a ripple-like domain structure mainly governed by the dipolar interdot interactions in the dot array, which is experimentally confirmed by the MFM observation. (C) 2004 Published by Elsevier B.V.