Hexakis[p-(hydroxymethyl)phenoxy]cyclotriphosphazene was prepared by the reaction of hexachlorocyclotriphosphazene with the sodium salt of 4-hydroxy benzaldehyde and subsequent reduction of aldehyde groups to alcohol groups by using sodium borohydride. The bromination reaction was carried out by using hydrobromic acid-sulfuric acid to give hexakis[p-(bromomethyl)phenoxy]cyclotriphosphazene. This compound was employed in initiating polymerization of 2-methyl-2-oxazoline to produce six-armed, star-branched polymers. Monofunctional initiator, NsPatOCeHeWOCe^-p-C^Br), was also prepared and used for initiating the polymerization of 2-methyl-2-oxazoline to result in linear polymers. Molecular weights and DP's per an arm of the polymers were determined by gel permeation chromatography and NMR, respectively. The molecular weight of the linear polymer measured by GPC was much higher than that of the star-branched polymer when their molecular weights determined by NMR were nearly same. The linear polymer (DP = 31) with a bulky hydrophobic head and a hydrophilic chain exhibited nonionic surfactant behavior, forming micelles above a polymer concentration of about 0.1% by weight. The star-branched polymers had a hydrophobic core and hydrophilic branches. The surface tension of the aqueous solution of the star-branched polymer (DP = 13.4 per branch) decreased very slowly as polymer concentration increased, and any evidence for forming micelles was not observed. N-Acetyl groups of star-branched polymers were removed by hydrolysis under acidic conditions to give the polymers with N-protonated poly(ethylenimine) branches.