Abstract: The design idea of Functionally Gradient Materials(FGM) is adopted to develop Metal Matrix Composites(MMCs) and the aluminum alloy matrix gradient composites reinforced with SiC particles are fabricated successfully. Experimental study is made on microscopic structure and compressive performance of the materials at high temperature. The results show that specific density of the materials can be increased and the gradient boundary layers can be eliminated by means of the second compressing and resintering power metallurgy technique, the true stress strain curves of the materials at the high temperature can be divided into two parts, strain hardening and strain weakening, the matrix has influence on strength at the high temperature but not the particles, relatively sliding motion is not found in the gradient boundary layers of the materials, and the deformation is related to the ways of gradient distribution of the materials.