Sustained silver (Ag) electroless deposition onto copper (Cu) surface was achieved from a simple and stable solution, which only containing silver salt, choline chloride (ChCl) and H2O, without using of catalyst and reductant. The mechanism of Ag deposition in ChCl-H2O solution was proven by ultra violet spectroscopy and cyclic voltammetry techniques. Through a study of the Ag coatings using atomic absorption spectroscopy, X-ray diffractometer and scanning electron microscope, we demonstrate that sustained deposition of Ag was achieved in ChCl-H2O solution with mole ratio higher than 1 ChCl : 5 H2O and the calculated activation energy of Ag deposition was 13.0 kJ.mol(-1). (C) 2013 The Electrochemical Society. [DOI: 10.1149/2.012304jes] All rights reserved.