Abstract: Combined studies on the behavior and effects of jetting penetrator charge when operated underwater were performed in simulation and experiment.Simulations of AUTODYN-2D hydrocode showed that a shaped charge with eccentric sub-hemisphere liner(SCESHL)can form jetting penetrator and produce precursor-follow effects underwater.Some influence of the ratio of length to diameter of SCESHL on the velocities of jetting penetrator were observed but appeared mildly on the penetration depth into water.Standoff influences significantly the shape,velocity gradient and penetration performances underwater of the jetting penetrator.The witness experiments underwater of SCESHL showed good agreement with the simulations.Optimum standoff is about 4 calibre of the SCESHL with 54?mm diameter.