Abstract: The preparation technology of rapidly solidified Al-18.6Si-4.34Cu-0.66Mg alloy has been described in detail in present paper.The relation between mechanical properties and structures of the high silicon-aluminium alloy was studied.Experimental results have shown that the strength, hardness and plasticity of Al-Si alloy were obviously improved. The tensile strength at room temperature reached 430MPa after solid solution and aging treatment. The tensile strength decreased with the increasing of test temperature. However,ab of 370MPa could be kept at 200C. Its wear resistance was increased by three thines when compared with that of hard aluminium.It is difficult to reach such high temperature stability and wear resistance for conventional high strengh aluminium alloy.