Abstract: Rapidly solidified Al-Si alloys are advanced structure materials. At present the alloys are mainly manufactured by rapid solidification/powder metallurgy(RS/PM) or spray forming(SF) routes; The alloys have extremely refined microstructure, homogenous composition distribution, non-equilibrium metastable phases, supersaturated solid solutions and high density of dislocations; The fracture mode of the alloys shows brittle feature. In this paper, the above mentioned contents are reviewed.