Zirconium diboride is one of the most promising ultra high temperature ceramics, which are urgently required in the development of hypersonic flight, atmospheric re-entry and rocket propulsion. In this work, the zirconium diboride coating is successfully obtained on different substrates by electrochemical deposition from a NaCl-KCl-K2ZrF6-KBF4 melt. The effects of current density, operating temperature, electrodeposition time and substrate materials on the microstructure and phase composition of the coating are also investigated by SEM, EDX, and XRD. Besides, the electrochemical reduction of zirconium, boron and zirconium diboride has been investigated by cyclic voltammetry and chronopotentiometry. The results show that various morphological and structure of ZrB2 coatings can be synthesized on stainless steel, graphite and carbon fiber reinforced carbon composite (C/C composite) substrates and the synthesis of ZrB2 mainly follow two subsequent electrochemical reactions and a chemical reaction. (C) 2016 The Electrochemical Society. All rights reserved.