Abstract: Polyaryletherketone has been widely used in biomedical fields such as trauma, spine and craniofacial repair owing to its high thermal stability, excellent mechanical properties, good biocompatibility and radiolucent permeability. Among these polymers, polyetherketoneketone (PEKK) shows better thermal stability and mechanical strength, and its diketone structure in the molecular chain makes it be more suitable for chemical modifications which greatly accelerates its clinical applications. In this paper, PEKK/hydroxyapatite (HA) composites were prepared by in-situ polymerization of PEKK at the surface of HA particles. The mass fraction of HA in the composites was above 50%, and HA particles were uniformly distributed in the PEKK matrix, by which the interface between PEKK and HA was increased significantly. The composites not only showed excellent mechanical properties (modulus 15.6 GPa, hardness 570 MPa), but also had a significant improvement in biocompatibility (surface contact angle of 60°, superior to titanium alloy; cell proliferation rate is 28%, higher than pure PEKK). Apparently, the overall performances are compatible with animal bones.