Abstract: This paper deals with the application of the static test results at low temperatureand low pressure to the actual engine operating conditions. In order to extrapolate the test-bed results of the cooling effectiveness of a turbine blade to actual conditions of engine operation, two methods are presented. ( 1 ) to derive the experimental relationship of cooling effectiveness by heat transfer analysis, ( 2 )to substitute the cooling effectiveness tests at low temperature and low pressurefor those at high temperature and high pressure according to the similarityprinciple. Five kinds of blades in the same shape but with different internalstructure have been tested for cooling effectiveness at various conditions. The results show that the two methods are satisfactory.