This paper presents the results of experimental analysis on the structural performance of steel, aluminum alloy and stampable sheets for bumper beams and the calculation results on the weight reduction of those bumper beams.Bending tests of straight beams, which were made of the three kinds of materials, were carried out in order to examine their structural performance. In consideration of failure modes, it was found that the maximum load and the absorbed energy of those beams can be evaluated by their material strength, their side-wall thickness and the height of their cross sections. Based on this evaluation method, the weight and the absorbed energy of the constant displacement were calculated using a common cross section. The weight reduction of aluminum alloy and stampable sheets is superior to 590MPa high tensile strength steel sheets. However, it was verified that applying ultra high tensile strength steel sheets can be equalized to the weights of aluminum alloy and stampable sheets.