The effect of different additives to the microstructure and phase properties of compact natural hydroxyapatite was studied. Compact HA was fabricated from HA powder obtained from bovine bones via calcinations and grinding processes. The sintering temperatures 1150oC and 1200oC were applied to increase the densification behaviour of natural HA. In this study, the effects of MgO and BaO to the microstructure and mechanical properties of natural HA were also being investigated. From the result, BaO increased the densification and microstructure developments of sintered natural HA. The average grain size distribution of 1.5μm can be clearly seen from the microstructure at temperature 1200oC for specimen doped BaO. However the density of specimen doped MgO give lower value of 57 % compared to pure natural HA. Thus, from the microstructure results, the MgO decreased the sintering rate of natural HA. On the other hand, the BaO increased the sinterability of specimen.
