An efficient synthetic route to cyclic polymers has been demonstrated through atom-transfer radical polymerization (ATRP) and subsequent ring-closing metathesis (RCM) reaction. Thus, telechelic poly(methyl acrylate) (PMA) having allyl groups was synthesized by ATRP of methyl acrylate with a difunctional initiator and the subsequent end-capping reaction with allyltributyltin. The following RCM reaction proceeded even under dilution in the presence of the Grubbs catalyst to give a cyclic PMA in a high