Abstract: In order to investigate the friction and wear properties of ZrO₂ reinforced hydroxyapatite (HA) composite coatings in bovine serum lubrication environment, HA bio-ceramic coatings whose ZrO₂ contents were 0, 15wt% and 30wt% respectively were prepared on titanium alloy substrates by plasma spraying technology firstly. Then, the phase formation and bonding strength of ZrO₂/HA composite coatings were analyzed. Finally, the friction and wear properties of ZrO₂/HA composite coatings in bovine serum lubrication environment were investigated with UMT-3 pin-disk wear tester, the morphologies of wear surfaces of coatings were observed and the wear mechanisms were analyzed. The results show that the main phase of HA coatings are HA, the ZrO₂ in 15wt% ZrO₂/HA composite coating and 30wt% ZrO₂/HA composite coating exists as cubic phase formation and the diffraction peak intensities are higher than that of HA. As the ZrO₂ content increasing, the bonding strength of coatings increases significantly. The ZrO₂/HA composite coatings have superior wear resistance and lower friction coefficients compared with those of pure HA coating. The wear mechanisms of pure HA coating are ploughing and abrasive wear primarily, while the wear mechanisms of 15wt% ZrO₂/HA composite coating and 30wt% ZrO₂/HA composite coating are brittle spalling wear.