Abstract: SiC particles reinforced Mg-2.51Zn-0.629Zr matrix composites with different contents of SiC particles were prepared by powder metallurgy.The microstructure and phase composition of the matrix alloy and the composites were analyzed by optical microscopy,scanning electron microscopy and X-ray diffraction.The variation relations of damping properties vs.frequency and temperature of the matrix alloy and the composites were investigated by means of LMA-1 low-frequency mechanical relaxation instrument.The results show that SiC particles distributed homogenously in the composites when the content of SiC particles was 15vol%.Compared with the matrix alloy,the addition of SiC particles obviously increased the damping properties of the composites.The damping properties of the composite with 9vol% SiC particles were the best,whose internal friction-temperature curves had internal friction peaks at 100-150℃,250-300℃ and 350-400℃.