In order to improve the interfacial behavior between SiC and Al, a surface layer of Cu was coated on SiC particles. The influence of pH value on the coating process was analyzed. A powder metallurgy method was used to prepare the Al-based metal matrix composites (MMCs). SEM, XRD techniques were used to characterize the sintered compacts. It was found that the optimized pH value during the coating process was 1~2. The specimen showed the maximum density when sintered at 750oC. Inter-metallic compound of Al3.21Si0.47 was detected which contributed to the enhancement at the interface between SiC and Al. The hardness of the composites is improved to 90 MPa.