Calcium oxide stabilized zirconia coatings have been deposited onto Ti-6Al-4V substrates by means of atmospheric plasma spraying and incubated in the simulated body fluid for different periods of time to investigate the formation of apatite on their surface. The phase composition and microstructure of the coatings before and after immersion were examined by scanning electron microscopy and X-ray diffraction. The results obtained showed that apatite can be formed on the coating soaked in SBF solution, which indicated that calcium oxide stabilized zirconia possessed good bioactivity.