Fly ash particulate reinforced aluminum matrix composites were successfully prepared by powder metallurgical method, in which the major fly ash particulates are spherical with 2.75 g/cm3 in density and 5⁶0 μm in diameters, consisting of SiO2, Al2O3 and Fe2O3 more than 85% in total weight percentages. SEM analysis reveals that there exists the aggregation of the fly ash particulates accompanying with the creation of minor gas hole. The density of the composites is slowly dropped with increasing the fly ash content. The hardness of the composites is increased with increasing the fly ash content less than 10%, while it is decreased with the fly ash content more than 10%.