The present work emphasis on behavior of zinc-aluminium alloy reinforced with silicon carbide particles when machined with wire electric discharge machining process (WEDM). The difficulty faced by conventional machining is severe tool damage while machining metal matrix composites. Electrical discharge machining can be successfully employed for machining MMC in the place of conventional machining to reduce the tool damage and to produce complicated contours with superior finish. In the present study ZA43 reinforced with SiCp is machined by wire EDM process. Machining is carried-out by varying applied current of (2, 4 and 6amp.)’ pulse on time (4, 8 and 16^s) and pulse off time (5, 7 and 9^s) while other parameters such as voltage, dielectric flushing pressure, wire tension etc. are maintained constant. It is observed that reduction in the material removal rate and increase in surface roughness for increasing reinforcement percentage in the composite. It is also observed that applied current and pulse on time increases the material removal rate where as pulse off time has less effect on it.