In order to investigate the penetrating characteristics of earth penetrating weapons, a series of simulation experiments have been performed on 57mm diameter gas gun by launching long rod projectiles penetrating three kinds of concrete targets. These concrete targets are cement mortar, steel fiber reinforced concrete(SFRC) and the SFRC with a board made by tightly arranged corundum spheres inside. The experimental results indicate that the nose shape has important influence on the penetration depth, while targets are impacted by the same projectiles at the same velocity. The penetration depth into SFRC with the board is decreased about 11%, but the penetration depth into cement mortar is increased about 12% as compared with that into the SFRC.