Abstract: The artificial joint material of U HMWPE composite reinforced with coralline hydroxyapatite (CHA) in
different content s was prepared by the pressing formation method. A hip joint wear simulator was used to
investigate the biot ribological behavior of a CHA/ U HMWPE acetabular cup against a CoCrMo alloy femoral head in calf bovine synovia lubrication at 35 ℃±1 ℃. The experimental result s indicate that the addition of CHA powders to U HMWPE enhances the hardness of the composites , and decreases the wear rates under calf bovine synovia lubrication. When the addition of CHA powders is up to 20 wt % , CHA/ U HMWPE composites demonst rate the well designed performance of the hardness and biot ribological behaviors. The abrasive and fatigue wear are the main wear mechanisms for CHA/ U HMWPE composite cups. The sizes of the wear particles become larger with the increase of CHA powders addition.