Abstract: The mechanical properties and microstructure of hydroxypapatite/carbon nano-tube composite were investigated. The phase constitution was studied by XRD and the microstructure is observed by SEM. The bending strength and fracture toughness of the composite will be improved when different content of carbon nano-tube is added to hydroxyapatite. When the composite was sintered at a higher temperature, part hydroxyapatite will decompose sometimes which will result in the produce of Ca₃ ( PO₄)₂ and Ca₂P₂O₇. At the same time, part carbon nano-tube will decompose or change from one crystal to another. Carbon nano-tube can decrease the sintering temperature of hydroxyapatite, thus, the sintering temperature of the composite should be control led below 1100℃ and the fine crystal material will be obtained.