The purpose of this paper is to provide a deeper understanding of the wear behaviour of 7075 Al/SiC_p composites through a detailed examination of the subsurface regions beneath the worn surface and the wear debris. Such an examination indicates that the subsurface layer beneath the worn surfaces of the composite pins is composed of the mechanically mixed layer(MML) except the samples tested on 10N and 0.2㎧. In the result of phase analysis of MML, it consists of intermetallic compounds such as FeAl₂ or Al_(13)Fe₄ as well as the fine mixture of Al, SiC, α-Fe and Fe oxides in the previously reported literatures. The hardness of MML is about HK 700-800 and the presence of the very hard MML indicates more wear resistance than without MML. On the basis of the above experimental observations; the dominant wear mechanisms in mild and severe wear regime are examined.