An extruded member of Al—Mg—Si aluminum alloy specially composed of Mg, Si, Fe, Cu, Zn, Ti, etc. which has the equiaxed re-crystallized grain structure in which intergranular precipitates 1 μm or lager are separate from one another at large average intervals and there are many cube orientations over the entire thickness region thereof so that it excels in both flexural crushing performance and corrosion resistance. The extruded member is suitable for use as automotive body reinforcement members which need outstanding lateral crushing performance under severe collision conditions as well as good corrosion resistance.