Abstract: The national standard GB/T 229-2007 specifies the striker blade radius can be chosen as 2 mm and 8 mm. There must be a certain difference between them. So the impact performance was tested under room temperature for the same samples by two kinds of different radius blade. The results showed that the impact absorption power by 8 mm radius blade was greater than by 2 mm radius blade, but the difference was not obvious. The right method and corresponding blade radius should be chosen to avoid misjudgement results. When the impact performance of different materials was compared, only using the same radius blade, the results were comparable.