In this paper, the penetration process of anti-structure tandem projectiles are investigated by numerical and experimental methods. The used projectiles in this research have been composed of the forward shaped charge with conical copper liner and the following kinetic energy projectile with flat nose. For determination of cavity and tunnel geometry, at first follow projectile penetration test is done. In this process three shaped charge projectiles are tested. According to the same conditions for projectiles and concrete target, the obtained data of performed test are good agreement with each others. Then numerical simulation of forward and follow projectiles penetration are analyzed by finite difference hydro code; AUTODYN. The numerical results obtained from the forward projectile penetration have been compared with experimental results. The comparisons between experimental and numerical results for forward projectiles show good agreement with each other. At the end of this research, the residual velocities of the follow projectiles are investigated by numerical method. The results also indicate that the residual velocity of follow projectile increase due to the damage in the concrete target, that it is according to predictions.