Abstract: Impact fracture bshavior of SiC whisker reinforced 6061AL metal matrix composites has been studied by combining SEAM fractographic analysis and instrumented charpy testing.As compared with that of isotropic SiCw/6061Al composite in which SiCw were randomly oriented,the hot-extruded composite has higher impact toughness.It is shown that hot-extrusion improves the properties of SiCw/6061 Al composites.Delamination fracture phenomenon was observcd. The impact fracture models of SiCw/6061Al corriposites were discussed in detail. The impact fracture behavior of the composite after extrusion is different from that of the as-fabricated composite.The reasons why the impact toughness was improved by extrusion of SiCw/6061Al. were analysed.