Successive synthesis of well-defined star-branched polymers has been successfully achieved by a new iterative methodology based on living anionic polymerization. The methodology involves only two sets of reaction conditions for the entire iterative reaction sequence: (a) a coupling reaction of the benzyl bromide-functionalized polymer with poly(substituted styryl)lithium end-capped with 1-(3-tert-butyldimethylsilyloxymethylphenyl)-1-phenylethylene to link two polymer chains and introduce 3-tert-butyldimethylsilyoxymethylphenyl group(s) of benzyl bromide precursor(s) and (b) a transformation reaction of the introduced precursor(s) into benzyl bromide functionality (functionalities) by treatment with (CH3)(3)SiCl-LiBr. By repeating these two reactions, an array of asymmetric star-branched polymers were successively synthesized. They involved 3-arm ABC, 4-arm. ABCD and A(2)B(2), and 6-arm A(2)B(2)C(2) stars whose A, B, C, and D segments are polystyrene, poly(α-methylstyrene), poly(4-methylstyrene), poly(methyl methacrylate), or poly(tert-butyl methacrylate), respectively. Their high degrees of compositional, molecular weight, and architectural homogeneity as well as narrow molecular weight distributions (M-w/M-n < 1.05) were confirmed by the analytical results of SEC, H-1 NMR, VPO, and SLS. The poly(tertbutyl methacrylate) segments of the A(2)B(2)C(2) star-branched polymer were readily and quantitatively hydrolyzed under the acidic conditions. As a result, a new ionic A(2)B(2)C(2) star having poly(methacrylic acid) segments was obtained.