Abstract: The experimental investigation on slot film cooling effectiveness was conducted with different blowing rates of the sample gas—CO₂,by using Heat-Mass Transfer Analogy method.The empiric formulas for calculating slot film cooling effectiveness were derived from the test data according to the turbulence-mixing model.The same experiment was also conducted with the mixing jet flow normal to the wall,and the disturbing action on film cooling downstream of the jet flow was determined.The results showed a great difference between the effects of different mixing flows on the film cooling.