A comprehensive set of amphiphilic star-shaped block copolyethers with a fixed molecular weight and composition was synthesized via the t-Bu-P-4-catalyzed ring opening polymerization (ROP) of 2-(2-(2-methoxyethoxy)-ethoxy)ethyl glycidyl ether as a hydrophilic monomer and decyl glycidyl ether as a hydrophobic monomer. The three and four-armed star-block copolyethers, i.e., the (AB)(3)-, (BA)(3)-, (AB)(4)-, and (BA)(4)-type star-block copolyethers, where A and B represent hydrophilic and hydrophobic blocks, respectively, were synthesized by the sequential t-Bu-P-4-catalyzed block copolymerization using tri- and tetra-alcohol initiators, respectively, according to the core-first method. The homogeneous growth of each arm was confirmed by cleaving the linkages between the initiator residue and polyether arms. The synthesis of the A(2)B(2)-, AB(2)-, and A(2)B-type miktoarm star copolyethers was achieved by the combination of the t-Bu-P-4-catalyzed ROP and azido-alkyne click chemistry. The azido- and ethynyl-functionalized precursor polyethers with the predicted molecular weights were separately prepared by the t-Bu-P-4-catalyzed ROP with the aid of functional initiators as well as a terminator. The intermolecular click reaction of the precursors provided the desired miktoarm star copolyethers. All the obtained star-shaped block copolyethers had a comparable monomer composition (degree of polymerization = 50:50) and total molecular weight (ca. 22 200 g mol(-1)) with a narrow dispersity (<1.05). The hydrodynamic diameter and the cloud point analyses for the aqueous micellar solution of the amphiphilic star-shaped block copolyethers revealed that the self-assembly properties were affected by the block arrangements and branched architectures of the amphiphilic polymers.