AP40　glass-ceramic　coatings　on　TiAl6V4　substrate　were　deposited　by　HVOF　process.　The　morphology,　microstructure　and　phase　compositions　of　the　coatings　were　studied　by　means　of　optical,　scanning　electron　microscopy　and　X-ray　analysis.　The　effects　of　heat　treatment　on　the　microstructure　and　mechanical　properties　of　coatings　were　also　investigated.　The　tensile　bonding　strength　of　the　coating　was　evaluated　in　accordance　with　the　DIN　EN　582-1994.　The　results　show　that　the　typical　lamellar　microstructures　of　AP40　coatings　which　contain　little　porosity　and　unmelted　powder.　The　phases　is　made　up　of　HA,　FA,　W　(β-wollastonite)　and　so　on;　The　spray　parameters　influence　significantly　the　porosity　of　the　coatings.　A　suitable　heat-treatment　can　increase　the　coating　crystallinity,　reduce　the　porosities　and　increase　the　bond　strength.