In the first part of this article, the method for preparation of heteroarm star (AnBnstar-block) copolymers from diblock macromonomers possessing central functional groups is reviewed. These diblock macromonomers formed a microphase-separated structure in the solid state. The central functional groups at the position of the block junction were located regularly at the domain interface. The microgelation of diblock copolymer films formed AnBnstar-block copolymers by organization effects. The second section reviews the methods for preparation of (AB)nstar-block copolymers from diblock macromonomers possessing a terminal vinylbenzyl group. The microgelation in micelles between diblock macromonomers and linking agent also formed (AB)nstar-block copolymers. Finally, the phase stability criteria of these star-block copolymers are reported briefly.