Two-component hyperbranched copolymers were prepared by the living anionic polymerization technique. The first-generated polystyrene (PS) stars (IG-S) were prepared by copolymerization of poly(4-methylstyrene)-block-polystyrene diblock anions with divinylbenzene. The peripheral 4-methylstyrene blocks in the arm were metalated with s-butyllithium/tetramethylethylenediamine complex in cyclohexane. The second-generated hyperbranched copolymers (2G-HC) were prepared by anionic copolymerization of such 1G-S polyanions with isoprene in tetrahydrofuran. We studied the solution-properties of such hyperbranched copolymers, 2G-HC, in benzene (good solvent). The 2G-HC behaved like soft spheres or loose star-structures that were constructed with flexible chains in the inner pal ts. On the other hand, the 2G-HC (PS blocks 31.9 wt%) formed unimolecular micelles even in a high concentration of more than 1 wt% of polymer concentration in a selective solvent such as cyclohexane.