A variety of benzyl ether-type dendron units were introduced as an ester substituent of diazoacetates, and their Pd-initiated polymerization behavior was investigated in detail. Because of the steric effect of the bulky dendron units, the monomers afforded polymers with narrow molecular weight distribution (MWD), and the polydispersity index became smaller with the increase of the bulkiness of the ester substituents. Narrow MWD polymers were also obtained by copolymerization of the dendron-containing monomers with ethyl diazoacetate bearing a sterically less bulky substituent and polymerization of dendron-containing monomers bearing 3,5-bis(alkoxycarbonyl)phenyl groups at its periphery. Deprotection of the alkoxycarbonyl groups of the latter polymerization products yielded dendronized polymers having multiple carboxy groups around their rigid main chains, whose pH-responsive behavior in aqueous media was significantly different from that of the corresponding vinyl polymers with the same side chains.