Metal matrix composites (MMCs) are engineering materials in which a hard ceramic component is dispersed in a ductile metal matrix in order to obtain characteristics such as hardness and corrosion resistance. Corrosion resistance is one of the important properties of nanocomposites; however, the corrosion mechanism of the Al- SiC nanocomposite has not yet been determined. .In this study, bulk Al-5% SiC nanocomposite was prepared using mechanical alloying and the hot press method. Corrosion behavior was then investigated using EIS techniques such as Nyquist and the Bod diagram. A larger charge transfer resistance was found for the Al- SiC nanocomposite by the EIS diagrams, confirming its corrosion resistance in a 3.5wt% NaCl solution.