We have been studying the plastic deformations of some steel beams under concentrated impulsive loading and recognized that our analytical methods proposed were quite in good agreement with the experimental results. So we carried out the experiments on the plastic deformations of some steel beams under equally distributed impulsive loading to examine whether the analytical methods could be enlarged or not. This time we treated the three cases of cantilever beams, simple and fixed ones in both ends under symmetrical equally distributed impulse. More details are described in the following articles.