Abstract: A new kind of composite with the matrix of pure magnesium was fabricated and its mechanical properties and damping capacity were studied in this paper. It was found that the strength of the magnesium matrix composite was improved largely compared with that of pure magnesium, however, its damping capacity dependent on strain amplitude was decreased due to the addition of the reinforcements. It was also proved that the effective damping mechanism in the magnesium matrix composite was G L dislocation damping model, the same way as that in the pure magnesium metal.