Numerical　approach　has　been　conducted　to　compare　the　film　cooling　characteristics　of　one　end　or　both　ends　trenched　holes.　The　influence　of　different　slot　configurations　on　the　adiabatic　cooling　effectiveness　and　discharge　coefficients　from　the　point　view　of　flowing　mechanism　was　revealed.　It　is　found　that　the　trenched　holes　can　improve　the　film　cooling　effectiveness　especially　for　the　short　double　end　trenched　hole.　At　low　blowing　ratio,　the　inclined　trench　is　superior,　at　high　blowing　ratio,　narrow　trench　wins.　The　rectangular　trench　increases　the　aerodynamic　loss,　while　the　inclined　trench　avail　the　decrease　of　the　aerodynamic　loss.　©　2008　Inderscience　Enterprises　Ltd.