Owing to the plates are commonly used in marine structures which are subjected to static, periodic or random loads. This investigation addresses the problem of transient responses of a stiffened plates subjected to an underwater explosion with the nonlinear finite element code ABAQUS was carried out. The reliability of the results was verified via the Ramajeyathilagam's experiments. In view of the above, this study elucidates the dynamic responses of stiffened plates in accordance with different ribs and shock loading. In addition, This investigation proppsed a approximate estimation method which used the principle of energy conservation could rapidly predicted the shock resistance of stiffened plates. The studies presented in this paper attempt to supply a reasonable comprehensive account, which will be used in designing ship hulls so as to enhance resistance to underwater shock damage.