Abstract: Film cooling characteristics of a turbine blade's leading edge with two rows cooling orifices were investigated.The flow and heat transfer characteristics about two rows of coolant at turbine blade's leading edge were acquired in the study.Furthermore,this paper calculated film cooling effectiveness when the injection angle was 25°,35°,45°and 65°.The computed results were presented in the form of adiabatic effectiveness contours on the blade surface and compared with experimental results.It was found that the strength and the size of vortex could be reduced by decreasing injection angle.It's proven that the best cooling effectiveness is provided by a small injection angle of 25°to the stagnation line.The results show that the transportation of two rows of staggered coolants is complicated.It's also shown that two-layer k-ε turbulence models are better than common k-ε turbulence models,and the description of coolant jet flow field in the turbine cascade is reasonable.