Abstract: The main objective of this study is to explore the deformation feature and damage pattern of a steel plate under the synergetic effects of blast and fragments loading. The combined blast and fragments loading effects under the condition of cast TNT and prefabricated fragments acting on a steel plate, are sim-ulated using the finite element program ANSYS/LS -DYNA. The flight of fragments driven by the charge is predicted, and the blast loading and fragments loading are analyzed respectively, while the deformation and damage characteristic under the combined loading are compared with experiment results. The simulation re-sults agree relatively well with the experimental results. Meanwhile, it is seen that the fragment at the cen-ter of the charge bottom has the highest velocity and the lowest velocity occurs at the edge. Under the exper-imental condition, blast reaches the structure first and fragments impact subsequently, and the total kinetic energy of fragments is much larger than that of blast wave and explosion products transmitted to the struc-ture. The punched hole appearing in the central region of the steel plate is mainly caused by the dense frag-ment cluster, which should be treated as the main target load for protective structures.