Abstract: A short carbon fiber (C_f) reinforced hydroxyapatite (HA) bio-composite was prepared by in-situ processing. In order to improve the interfacial bonding of C_f/HA bio-composite, C_f surface was modified by oxidation treatment. The pure HA structures, C_f surfaces and fracture surface morphologies of the bio-composite were analyzed using XRD, FTIR and SEM, respectively. The mechanical properties of the C_f/HA were tested by a universal testing machine. The result shows that after oxidation treatment the surface of C_f exhibits rough and a lot of —OH, —COOH appears. The bio-composite has the maximum relative density and the excellent mechanical properties when C_f mass fraction is 3%, flexural strength and flexural modulus reach the maximum values of 130 MPa and 36 GPa. SEM fracture surface morphologies of C_f/HA bio-composite indicate that when the mass fraction is less than 6%, C_f uniformly disperses in the HA matrix.