A synthetic route for highly stable electrically conductive core-shell nanoparticle was developed. It involves the synthesis of multiarmed poly(n-butyl acrylate-b-polystyrene) (PBA-b-PS) starburst block copolymers via the atom transfer radical polymerization method from polyfunctional initiators under very dilute condition using n-butyl acrylate and styrene as monomers, sequentially. Both NMR and gel permeation chromatography analyses reveal that the as-synthesized copolymers had a well-controlled molecular weight with a polydispersity of below 1.2. Then, the outer PS shell of the star copolymer was converted into hydrophilic poly(p-styrenesulfonate) with acetyl sulfate to generate amphiphilic PBA-b-PSS unimolecular micelles. The H-1 NMR spectrum confirmed that a sulfonation of almost 100% was reached without hydrolysis of the side butyl ester chain on PBA blocks. Finally, the oxidative propagation of 3,4-ethylenedioxythiophene (EDOT) on the PSS chains was carried out by counterion-induced polymerization to produce a stable aqueous dispersion of star-shaped PBA-b-PSS/PEDOT complex, which can be visualized as a conducting core-shell nanoparticle. The obtained products were characterized by FT-IR and UV-vis spectroscopy. All thin films prepared by casting from 4-, 6-, and 12-armed complexes exhibited excellent flexibility and strong adhesion to glass substrate; their conductivities were determined by the four-point probe method to be 6.7, 4.9, and 6.8 mS/cm, respectively.