Abstract: The frequency distribution of impact energy of turbine stator blade steel 1Cr12Mo was analyzed based on SPSS software. Results showed that the dispersion of impact energy was large and the test values were not followed the normal distribution absolutely. The minimum test specimen should be calculated according to the dispersion coefficient under given relative error limit was proposed. For the average values of abnormal distribution test results cannot reflect the true impact resistance of material correctly,a method was recommended that the safety impact energy could be expressed as percentiles calculated by SPSS software.