Interlamellar　bonding　is　an　important　factor　controlling　the　mechanical,　thermal　and　electrical　properties　of　plasma　sprayed　ceramic　coatings.　In　order　to　understand　the　formation　of　limited　interlamellar　bonding,　a　theoretical　model　is　proposed　based　on　the　concept　of　the　intrinsic　bonding　temperature.　The　numerical　simulation　of　the　interface　temperature　between　a　molten　splat　and　underlying　splats　was　performed　for　splats　with　uniform　and　non-uniform　thickness,　in　order　to　reveal　the　conditions　for　the　interlamellar　bonding　formation.　The　interlamellar　bonding　ratio　was　theoretically　estimated　based　on　the　bonding　forming　conditions.　The　features　of　interlamellar　bonding　revealed　by　the　simulation　agree　well　with　the　experimental　observations.　The　bonding　ratio　of　plasma　sprayed　coatings　is　significantly　influenced　by　the　distribution　of　splat　thickness.　According　to　the　distribution　of　Al2O3　splat　thickness　in　the　coating,　the　theoretical　estimation　of　bonding　ratio　yielded　a　value　of　0.41　for　the　plasma　sprayed　Al2O3　coating　at　the　ambient　atmosphere　conditions,　which　is　reasonably　consistent　with　the　observation　value.　Therefore,　the　limited　interlamellar　bonding　can　be　reasonably　explained　based　on　the　sufficient　condition　that　the　maximum　interface　temperature　between　a　molten　splat　and　underlying　splats　is　larger　than　the　intrinsic　bonding　temperature.