Yttria　stabilized　zirconia　(YSZ)　coatings　were　deposited　onto　Ti-6Al-4V　substrate　through　a　microplasma　spraying　(MPS)　technique　and　incubated　in　the　simulated　body　fluid　(SBF)　for　different　periods　of　time.　The　apatite　formation　on　their　surface　was　investigated　to　evaluate　the　bioactivity　of　the　coatings.　Surface　morphologies　and　structural　changes　in　the　coatings　before　and　after　immersion　were　analyzed　by　optical　microscope　(OM),　scanning　electron　microscopy　(SEM)　and　X-ray　diffractometer　(XRD).　Results　show　that　yttria　stabilized　zirconia　coatings　can　be　produced　by　MPS.　XRD　patterns　show　that　the　coatings　appear　to　be　primitive　tetragonal　phase.　SEM　observations　show　that　the　ZrO2　coating　appear　to　be　rough,　porous　and　melted.　The　cross-section　morphology　of　the　coatings　was　very　dense.　Apatite　layer　formed　on　the　surface　of　coatings　after　4　weeks　immersion　in　SBF　solution,　indicating　that　the　YSZ　coating　possesses　definite　bioactivity.