Abstract: An enlarged test blade of gas turbine has been investigated experimentally for flow resistance and heat transfer in its cooling passages.Air entered the radial cooling channel inside the leading part of the blade and contrary flowed downward into the passage between two plates while the air flow reached to the top.The bulk of the air stream flowed through five holes on the plate into the chordwise wedged passage with three pin-fin rows and exhausted to the atmosphere.The experimental results of the pressure distribution,the flow resistance under heating and without heating,and the distribution of the local heat transfer coefficient in the cooling passages of a gas turbine blade are presented.Therefrom an emperic formula is obtained.