Abstract: The blast-resistance capacity of different polyurea-coated plates and box structures subjected to blast loads was investigated. For polyurea-steel plates,two methods were adopted:steel plates of three thicknesses(2.0,1.5 and 1.2 mm) and two types(no polyurea and with polyurea on the front face)with the same areal density of 15.7 kg/m<sup<2</sup< were considered under explosive loading by 40 g TNT; steel plates of two thicknesses(1.5 and 1.2 mm) and three types (no polyurea,with polyurea on the front face and with polyuria on the back face)with the same steel thickness respectively were subjected to 60 g TNT. Then experiments of polyurea-steel box under implosive loading were conducted by 140 g TNT.Deformation and failure were compared with each event and effects of polyurea coating on the performance of structures were analyzed further.Results from the experiments reveal that polyurea coating does not contribute to the performance of steel plates with the same areal density,while polyurea coating can improve the blast resistance of steel plates and steel boxes with the same steel thickness under explosive and implosive loading. And polyurea cast on the back face exhibits better performance than that on the front face.