Abstract: 80%Mg＋20%HA(hydroxyapatite) composite powders were mechanically milled with high energy by dry milling method,and then compacted into  15 mm×4 mm flake samples and sintered at 500 ℃ for 1 h.Compression strength and hardness of the sintered composites were determined,the fracture morphology and microstructure were observed with scanning electronic microscopy and optical microscopy.The results show that the composite powders were refined as the milling time increased,and the HA dispersed uniformly in Mg substrate.Both the compression strength and hardness of the sintered composites were improved.When the composite powders were milled for 30 h,a better match between mechanical properties(compression strength 256.3 MPa;hardness 684 HV) and microstructure was realized.The Mg/HA composite is a biological material with relatively good bioactivity,but its corrosion resistance needs further improvement.