The writers carried out experimental studies and theoretical conceptions on the plastic deformations of cantilever beams, simple and fixed beams under large impulse, and recognized the approximate calculating methods we proposed were quite in good agreement with the experimental results, so we tried to apply our methods to the more complicated structures, for instance continuous beams and rahmen structured etc. In this paper we treated the plastic deformations of continuos beams under large concentrated impulse. More details are described in the following sections.