Abstract: The process of formation and penetration against water-partitioned armor of explosively formed projectiles is studied. The flight characteristics and law of penetration are studied with high speed photography and electric probe technique. Experimental results showed that shaped charge with variational-wall-thickness hemispherical liner may be beneficial to the penetration into water-partitioned armor and the results concluded. Provide some valuable advices for the design of shaped charge configuration of torpedo warheads.