For achieving an excellent bioactivity and mechanical properties, silica and titanium-reinforced hydroxyapatite composite coatings were deposited onto 304 SUS substrate by using a gas-tunnel plasma spraying system. A commercial HA powder of average size 10-45 mm was blended with fused amorphous silica and titanium powders with HA: SiO2: Ti wt.% ratios of 75: 15: 10 respectively. The mixed powders have been plasma sprayed at various plasma gas flow rates (Ar) of 120, 140, 160 and 170 l/min. The morphologies and structure of the resulting coatings were investigated by scanning electron microscope, X-ray diffraction and electron dispersive spectroscopy. Hardness, abrasive wear resistance and adhesive bonding strength properties of the as-sprayed composite coatings were investigated. Silica and titanium provide reinforcement via increasing the bonding strength of HA particles and abrasion resistance. A heat treatment for the sprayed coatings was carried out at a temperature of 650 degrees C for 2 h in ambient oxygen and the change in the phase structure was analysed by X-ray diffraction. The results showed a formation of TiO2 ( rutile) phase due to titanium oxidation at 650 degrees C. On the other hand, the heat treatment enhanced the crystallinity of HA coating by transferring the non-apatite tri-calcium phosphate phase into apatite phase. The corrosion resistance measurement by polarization method confirmed the improvement of corrosion resistance of the composite HA/SiO2/Ti coatings compared with the pure HA. However, the annealed samples showed lower corrosion resistance compared with as-sprayed samples. (C) 2008 Elsevier B. V. All rights reserved.