Abstract: Water resistance was an important index which will determine the properties of thermal barrier strip. The comparison between the two different methods to test water resistance was performed according to GB/T 23615.1-2009 standard, including the boiling water test and the immersion test at normal temperature. It was found that the testing results of the different methods were close, but the immersion test at normal temperature was more severe and more representative of the water resistance property of thermal barrier strip.