This paper presents the ballistic limit study for the water-filled aluminum tank. The objective was to determine the ballistic limit for the rear tank wall by using numerical method. Commercial software Altair Hyperworks 12.0 was employed for this study. The finite element coupled with smoothed particle hydrodynamics (SPH) was developed to model the perforation of fragment simulating projectile (FSP) towards water-filled tank. Verification of the results was done by comparing with the experiment results. The results showed that there were four main phase failures occurred, which were shock phase, drag phase, cavitation phase and exit phase. The ballistic limit for the rear wall was 479.27 m/s.