PURPOSE: To manufacture a high strength structural member under low working ratio by executing compacting treatment to aggregate of raw material powder composed of main powder consisting of crystal phase alloy powder and adding powder containing amorphous single phase alloy powder.

CONSTITUTION: The light alloy raw material powder containing the main powder and the adding powder is made to the mixed powder whose volume fraction ratio P(Vf) of the adding powder is set at ≥5%. Then the above main powder is made to the crystal phase alloy powder having volume fraction ratio C(Vf) of the crystal phase at 100% or near this. Further, the above adding powder contains the crystal phase and the amorphous phase and consists of at least one of the mixed phase alloy powder containing the amorphous phase at ≥5% volume fraction ratio A(Vf) and an amorphous single phase alloy powder contg. 100% amorphous phase by the volume fraction ratio A(Vf). After compacting this aggregate of raw material powder, by executing hot extrusion, the high strength structural member is obtd.