This research aims to improve the mechanical properties and corrosion resistance of magnesium based composites with addition of zinc and manganese as alloying elements. Mg-Zn-HA, Mg-Mn-HA and Mg-Zn-MnHA composites with Mg-HA composite as control have been fabricated through powder metallurgy route. 1.5wt% of alloying elements was added into magnesium matrix for each composite. The composites were prepared by mechanical alloying followed by compaction under 400 MPa and sintering at 400°C. The results showed that with additional alloying element, micro-hardness, compressive strength and corrosion resistance of composites are significantly enhanced compared with Mg-HA composite. The Mg-Zn-Mn-HA composite showed the best properties among Mg-based composite with density, micro-hardness and compressive strength of 1.77 g/cm3, 65.5 HV and 210 MPa respectively all in range of properties of human bone. Immersion test in Hank’s Balanced Salt Solution (HBSS), weight loss of Mg-Zn-Mn-HA reduces to 0.61% when immerse for 5 hours and to 6.20% for 24 hours immersion.