Star polymers with end-functionalized arm chains (surface-functionalized star polymers) were synthesized by the in situ linking reaction between ethylene glycol dimethacrylate (linking agent) and an alpha-end-functionalized linear living poly(methyl methacrylate) in RuCl2(PPh3)(3)-catalyzed lhing radical polymerization; the terminal on the surface functionalities included amides, alcohols, amines, and esters. The star polymers were obtained in high yields (75-90%) with initiating systems consisting of a functionalized 2-chloro-2-phenylacetate or -acetamide [F-C(O)CHPhCl; F = nPrNH-, HOCH2CH2O-, Me2NCH2CH2O-, or EtO-; initiator] and n-Bu3N (additive). The yield was lower with a functionalized 2-bromoisobutyrate [Me2NCH2CH2OC(O)CDMe2Br] initiator or with Al(Oi-Pr)(3) as an additive. Multi-angle laser light scattering analysis showed that the star polymers had arm numbers of 10-100, radii of gyration of 6-23 nm, and weight-average molecular weights of 1.3 X 10(5) to 3.0 X 10(6), which could be controlled by the molar ratio of the linking agent to the linear living polymers.