Abstract: A method of observing gouge mark for judging the misalignment type of impact testing machine was introduced.The method can be used for qualitatively judging the type of misalignment when the testing machine is out of accuracy,such as over worn anvil,uneven worn anvil,anvil with excessive surface roughness,chipped anvil,bent pendulum,off-center striker and off-center specimen.The method is easy to learn,simple and practical,and can be used for the routine inspection of impact testing machine.It should be popularized and applied as one of the routine quality control methods in laboratory.