Electrospark deposition (ESD) is a promising process to produce hard and wear-resisting coatings on metallic substrates. In this paper. microstructure and interfacial characteristics of the WC92-Co8 coated-titanium are presented. A metallurgical bonding between the coating and substrate is obtained. The Ti element was found to distribute in WC92-Co8 at the metal pool, as well as the interface by diffusion. Some new phases were produced in the coating layer due to the chemical reaction during the ESD process. Experimental observation and thermodynamic analysis were utilized to study the mechanism of ESD. (C) 2004 Elsevier B.V. All rights reserved.