Abstract: The particle velocities in the free surface of the Al<sub<2</sub<O<sub<3</sub< ceramic specimen were recorded by DISRA system. The experimental results show that the leading edges of the particle velocity curves are getting flat to varying degrees under the different experiment conditions, which demonstrate the characteristic of the plastic-like behavior under impact loading. Meanwhile, in the experiment, the Hugoniot elastic limit of the ceramic attenuates with the thickness of the specimen, which reflects the features to some degree on the dynamic response of the Al<sub<2</sub<O<sub<3</sub< ceramic.