PURPOSE: To stably manufacture a composite material lightened in weight, having high strength, and excellent in damping characteristic, etc., by using a light-metal material powder as base material, by mixing specific amounts of microsphere having lower specific gravity and higher softening point than those of the base material with said base material, and by subjecting the resulting mixture to solidification with heating so that the mixture is softened in part.

CONSTITUTION: The microsphere (borosilicate glass, etc.) having lower specific density and higher softening point than those of the base material composed of light-metal material such as Al alloy, etc., is added to the powder of the above base material by 10W70vol%, and they are mixed by agitation. This mixture is heated so that it is softened in part while the balance retains its solidified state, followed by solidification. In this way, the mixture is solidified with maintaining the state where the microsphere is uniformly dispersed in the base material, so that composite light-metal material combining light weight with high strength and excellent in damping characteristic, etc., can stably be obtained.