Hydroxyapatite whisker and platelet were synthesised by the hydrolysis of alpha-tricalcium phoshate (α-TCP) in H₂O system and etanol/H₂O system at 70°C and atmospheric pressure, thus avoiding severe processing condition, such as in hydrothermal synthesis. The hydroxyapatite prepared by this process was analysed by X-ray diffractometry and transmission electron microscopy observation. The effect of ethanol addition into H₂O on the hydrolysis of α-TCP to hydroxyapatite was also examined. The hydrolysis rate of α-TCP to hydroxyapatite was inhibited in the ethanol/H₂O system. It was found that the morphology and the aspect ratio of hydroxyapatite could be controlled by adding ethanol into H₂O during the hydrolysis reaction of α-TCP.