Abstract: Dynamic and static resistances as well as resistance of steel bar to projectile when projectile colliding with steel bar are taken into consideration in the proposed engineering analytical model. Penetration depth and displacement, deceleration, velocity histories of projectiles with different impact velocities during penetration are calculated by using the proposed engineering analytical model and these calculated results are in good agreement with the experimental results. The peak rigid-body accelerations are between -12 000 g and -15 000 g (acceleration of gravity). The proposed model can represent the movement states of a projectile during its penetrating a semi-infinite reinforced concrete target, and it can be used to analyze the effect of configuration, size and mesh size of a steel bar on penetration depth and process.