To investigate the blast resistance of sandwich structures with cellular metallic core, the dynamic response of sandwich structures with MHS(metal hollow sphere)and aluminum foams were studied both experimentally and numerically by employing ANSYS/LS-DYNA. Experimental results prove that sandwich structure with MHS can be used to resist blast. According to the parametric studies, the sandwich structures with thin inner face sheet and thick outer face sheet have stronger blast resistance than others. Comparison between sandwich structures with metal hollow spheres and those with aluminum foams was studied experimentally and numerically and the results demonstrate that structures with aluminum foam have advantage over the other in most cases. Also the results show that sandwich structures with interlaced hollow spheres have a better performance than those with paratactic hollow spheres. Moreover, it's inferred that the density graded core with the biggest density as the first impact layer and the least density as the last layer has more benefits in energy absorption. The conclusions are referable in the optimization of sandwich structures.