Abstract: The microstructure near the penetrated hole of a 60 steel target was analyzed by launching a navy 37 gun. It is shown that the melting of 93 W alloy occurs under the high pressure in the process of penetration because there is a component of 93 W alloy on the surface of the penetrated hole. An adiabatic shear band formed along the main shear stress around the penetrated hole is approximately consistent with the direction of plastic deformation slip lines in static state. Non-homogenous deformation inside the adiabatic shear band causes microcracks and micropores. Two kinds of adiabatic shear bands were found, including the deformed band and the phase-transformed band.