In this article, a copper-in-polymer-gradient composite film (CPGCF) was synthesized by electrochemical strategy via reducing a solvent-swollen cathode film (SCF). The latex nanoparticles of a ternary copolymer including styrene, butyl acrylate, and acrylic acid structural units play the key role to form well-graded copper distribution in this ternary copolymer matrix through the porous morphological structure developed by latex nanoparticle semimelt joining. The morphological structure along cross-section of CPGCF includes three layers: (1) a dense copper layer in ternary copolymer matrix whose most outside was originally attached to cathode in electrochemical reactor, (2) a shrublike layer that grew from dense copper layer, and (3) a clear layer in which there is no obvious reduced copper phase whose most outside was originally contacted with liquid electrolyte medium in electrochemical reactor. As experimental aspects, the influences of emulsion polymerization conditions of ternary copolymer, predrying time and temperature of SCF, dc voltage in electrochemical reduction on CPGCF structure were investigated. (C) 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012