A　square　channel　of　a　geometry　commonly　used　in　heavy-duty　gas　turbine　blade　as　forced　convection　cooling　channel　was　experimentally　studied.　The　effect　of　Reynolds　number,　wall　heat　flux　and　mist　mass　flow　rate　on　the　heat　transfer　characteristic　of　mist/steam　cooling　channel　wall　were　analyzed.　A　experimental　correlation　of　heat　transfer　was　developed　to　account　for　mist　flow　working　conditions　and　channel　wall　heating　conditions.　Results　show　the　heat　transfer　coefficient　of　mist/steam　two-phase　flow　is　significantly　higher　than　the　pure　steam.　Heat　transfer　performance　of　mist/steam　decreases　with　increasing　of　heat　flux　and　increases　with　increasing　of　Reynolds　number　and　mist　mass　flow　ratio.　The　average　heat　transfer　coefficient　of　upper　wall　surface　is　lower　13%　than　bottom　wall　surface　under　higher　heat　flux　and　lower　mist　mass　flow　ratio,　while　in　the　case　of　low　heat　flux　and　high　mist　mass　flow　ratio,　this　ratio　increases　to　approximately　25%.　©　2015,　BUAA　Press.　All　right　reserved.