Abstract: A finite difference scheme with three order precision and TVD property and a multi block grid technique are adopted.The leading edge film cooling flow field in a turbine with two rows of coolant holes is numerically simulated based on the three dimensional N S equation solver.The characteristics of the flow and temperature fields,including the coolant trajectory,the interaction of two rows of coolant jets and the complicated distribution of film cooling adiabatic effectiveness in the region of leading edge are all expounded under different blowing ratios,injection angles and locations of coolant holes.The results show that the influences of different positions of coolant holes,their arrangement and the blowing ratios on the adiabatic effectiveness are obvious and complicated in the leading edge.