Abstract: A copper electroplating composition for integrated circuit interconnection is proposed, including a copper salt, an inorganic acid containing same anion as the copper salt, a suppressing agent and a polishing agent. This electroplating composition helps deposit copper into fine trenches with a high aspect ratio on a substrate, so as to form a surface-flat and void-free plated copper layer over the substrate by electroplating. It can therefore reduce the usage of polishing slurry and polishing time in a subsequent chemical mechanical polishing process, and also improve surface planarity of the copper later after being polished.