Amphiphilic cylindrical brush-coil block copolymers consisting of a polystyrene coil and a cylindrical brush block with poly(acrylic acid) side chains tire prepared by ATRP of t-butylacrylate from a block comacroinitiator. Upon acidolysis of the poly(t-butylacrylate), water-soluble polymers were obtained that were observed to form micelles consisting of 4-5 block copolymers on average in aqueous Solution. The star-like nature of such micelles was clearly visualized by scanning force rnicroscopy.