The　corrosion　resistance　of　thermal　barrier　coatings　against　CMAS　deposit　at　high　temperature　is　significantly　affected　by　the　microstructure　of　the　coatings.　Enhancing　the　bonding　ratio　between　splats　can　reduce　the　inter-connected　pores　and　then　obstructs　the　penetration　of　the　molten　CMAS　into　the　coatings.　In　this　study,　atmospheric　plasma　sprayed　ZrO2　contains　8　wt.　%　Y2O3　(8YSZ)　coating　with　improved　lamellar　bonding　ratios　was　deposited　with　full-molten　droplets　at　an　enhanced　deposition　temperature.　The　microstructure　of　the　dense　8YSZ　coating　and　conventional　8YSZ　coating　before　and　after　thermal　exposure　with　CMAS　were　characterized.　It　was　clearly　revealed　that　by　adjusting　the　microstructure　and　designing　a　ceramic　layer　with　high　bonding　ratio,　the　corrosion　resistance　of　the　thermal　barrier　coating　could　be　enhanced.　Moreover,　by　designing　double-ceramic-layer　(DCL)　TBCs　composed　of　a　porous　ceramic　layer　and　well-　bonded　ceramic　layer,　the　TBCs　with　high　CMAS　corrosion　resistance　and　low　thermal　conductivity　can　be　achieved.　©　Copyright　(2015)　by　ASM　International　All　rights　reserved.