The　optimal　spray　parameters　were　determined　by　experiments,　based　on　the　partially　melted(PM)　zone　percentage,　porosity　and　bond　strengh　of　the　coatings.　Microstructure　of　the　nanostructured　Al2O3-13wt%　TiO2(AT13)　compound　coating　sprayed　with　the　optimal　spray　parameters　was　analyzed　by　XRD,　SEM　and　TEM.　Microhardness　and　fracture　toughness　of　the　coating　were　studied　by　Weibull　distribution　and　wear　map　was　established　by　wear　experiments.　The　results　show　that,　nanostructured　coating　contains　fully　melted(FM)　zone　and　PM　zone,　the　increasing　of　the　critical　plasma　spray　parameter(CPSP)　promote　the　discreasing　of　the　PM　zone　percentage　and　the　increasing　of　the　bond　strength　of　the　coatings.　The　component　phases　of　the　powder　reacts　each　other　during　the　plasma　spraying　process.　FM　and　PM　zone　results　from　fully　melted　droplets　and　partially　melted　particles,　respectively.　Nanosized　crystals　and　amorphous　particles　exist　in　the　PM　zone,　liquid　phase　sintering　operates　in　the　PM　zone.　The　Weibull　distribution　analysis　shows　that　the　distribution　of　microhardness　and　fracture　toughness　of　the　coating　present　a　bi-modal　distribution,　which　is　correspond　to　the　bi-modal　microstructure　of　the　nanostructured　coating.　The　mean　value　of　microhardness　of　PM　zone　is　higher　than　that　of　FM　zone,　while　the　dispersity　is　higher.　The　mean　value　and　the　disparity　of　fracture　toughness　of　PM　zone　are　both　higher　than　that　of　FM　zone.