The modem gas turbine engines operate at high pressure ratio and consequently higher entryturbine temperatures. At high loads, this temperature exceeds the allowable metal-temperaturelimits. The turbine blades need to be protected to ensure theft integrity. The efficient coolingtechnique such as film cooling is therefore essential to protect the gas turbine blades. Theefficiency of this technique depends on several parameters, such as the injection blowing ratio,density ratio, mainstream turbulence intensity, mainstream pressure gradient, boundary layerthickness, injection angle, spacing between holes as well as their arrangement, and the bladegeometry. The main objective of this study was to make a numerical study on the first stage forboth profiles VKI and C3X turbine blades cascade with a leading edge showerhead film-coolingarrangement by using the commercial code Fluent v. 5.4. The governing equations for steady, t~vodimensional, turbulent, compressible flow are integrated over arbitrary two-dimensional controlvolumes with the aid of Gauss theorem. The present computational model seeks to a realistic filmcooled turbine blade. The code is used to study the combination of film and convection cooling.While most ofthe theoretical studies considered isothermal blade surfaces in thermal calculationsover the blade surfaces. The results indicated that the film cooling enhances adiabatic effectivenessand decreases the surface heat flux by six times that of uncooling blade. In case of increasing theblowing ratios or streamwise injection angle, the adiabatic effectiveness decreases gradually. Theeffectiveness for combined cooling is higher than that of film cooling only due to the combinationoffilm and convection cooling together. Also the film cooling effectiveness for the VKI profile ishigher than that ofthe C3X profile as a result ofthe better design shape of VKI profile. The modelhad been validated and tested with previously published experimental and theoretical results.These comparisons show a satisfactory agreement that permits an extension of the theoreticalstudy.