Abstract: Al₂O₃/Al composites of different volume fractions were produced by using reciprocating extrusion technology with pure Al powder and Al₂O₃ particle. Then the damping capacity of the composites was measured. Relationship of damping behavior and strain amplitude or frequency, and the contribution of different content of reinforced particles to damping capacity were investigated. The result shows that the Al₂O₃ particles homogeneously distributed in Al matrix, and the Al₂O_3P/Al composite prepared by reciprocating extrusion has an excellent damping capacity. The damping property improves with increase of the particles content. At low strain amplitude, the main damping mechanism of Al₂O_3P/Al composites is dislocation damping, whereas at high strain amplitude, interface-sliding damping becomes the main damping mechanism.