Abstract: The growth of pore pressure of clay under shock load infuence effective stress and strength of clay directly. Numerical analysis on the growth principles of pore pressure of clay under shock load provides theoretical references for dynamic responses analysis of clay and dynamic consolidation of clay medium. The transient shock load has been simplified into trial anger load and the transient dynamic elastic plastic finite element program has been programed. The dynamic responses of pore pressure of clay under shock load has been simulated. Some growth principles of pore pressure of clay under shock load have been concluded.The peak pore pressure attenuates exponentially with the increase of the horizontal distance and the augmentation of the depth. Calculation and analyses are in good agreement with monitoring datas of practical engineering case.