The　effects　of　the　slot　hot　blowing　of　the　hollow　stator　blades　on　the　size　of　secondary　water　droplets　and　the　thickness　of　the　water　film　were　experimentally　investigated　in　this　paper.　The　experiment　was　carried　out　on　the　turbine　blade　cascades　in　a　wet　air　tunnel　with　an　inlet　air　wetness　fraction　of　7.9%,　an　outlet　air　velocity　of　170m/s,　a　slot　width　of　1.0mm　and　a　slot　angle　of　45°　to　blade　surface.　The　Malvern　Droplet　and　Particle　Size　Analyser　was　utilized　to　measure　the　secondary　water　droplet　size　and　distribution　downstream　of　the　hollow　stator　blades　in　the　experimental　tests.　The　experimental　results　show　that　the　maximum　diameter　and　Sauter　mean　diameter　of　the　secondary　water　droplets　were　reduced　greatly　and　the　water　droplet　size　distribution　became　narrower.　The　larger　blowing　pressure　difference　resulted　in　the　smaller　secondary　water　droplets　and　the　narrower　water　droplet　size　distributions.　In　addition,　the　efficiency　of　water　separation　from　the　hollow　stator　blade　surfaces　was　higher　for　slot　on　the　suction　side　than　that　of　the　pressure　side　case.　Another　simplified　experimental　test　was　also　carried　out　on　the　flat　plate　to　investigate　the　effect　of　slot　hot　blowing　on　the　thickness　of　the　water　film　downstream　of　the　slot.　The　conductivity　probes　were　used　to　measure　the　thickness　of　the　water　film　downstream　and　upstream　of　the　blowing　slot.　The　results　show　that　the　slot　hot　blowing　reduced　the　thickness　of　the　water　film　downstream　of　the　slot,　which　was　affected　by　the　blowing　pressure　difference　and　temperature　difference　between　the　hot　blowing　air　and　the　main　airflow.　In　conclusion,　the　slot　hot　blowing　of　the　hollow　stator　blades　has　reduced　the　size　of　the　secondary　water　droplets　and　secondarily　has　evaporated　a　little　water　film　on　the　blade　surfaces.　Both　effects　are　beneficial　to　reduce　the　erosion　damage　to　the　rotor　blades.　Copyright　©　2008　by　ASME.