In the present work, formation possibility of surface layer containing tungsten carbide on AZ91 substrate by pulsed laser during surface melting was investigated. AZ91 magnesium substrate was initially sprayed with WC-Co powder by Air Plasma Spray (APS) process and then surface melted by pulsed Nd:YAG laser in different scan speeds. Optical cross sectional optical microscopy of the treated specimens confirmed formation of very fine structured layers. X ray diffraction analysis confirmed presence of tungsten carbides in the melted zones. Micro hardness results also showed that the hardness of the fabricated surface layer was almost twice of that of the base material.