Compositionally graded Al-SiCp composites were fabricated using pressureless infiltration process. Microstructure was examined and thermal properties were characterized for Al-SiCp composites. Al-SiCp composites with fairly uniform distribution and compositional gradient. of SiC reinforcement in the Al matrix though the thickness direction was successfully fabricated. The thermal conductivity of Al-SiCp composites was measured at room temperature, 200degreesC and 400degreesC using laser flash method. Thermal conductivity of Al-SiCp composites increases non-linearly with decreasing the volume fraction of SiC. Cyclic thermal shock fatigue tests were performed by immersing Al-SiCp functionally graded materials(FGM) into water from the various heating temperatures of 400degreesC, 300degreesC and 200degreesC, repeatedly. After cyclic thermal shock fatigue tests, micro-hardness was measured and formation of cracks was investigated.