This paper describes the load-displacement relationships and the strain distribution of beams. These beams are fabricated from high strength steel with low yield ratio, or high yield ratio. But the nominal tensile strength of these steels are 590N/mm^2, together. The large deformation behavior of these high strength steel beams are obtained by experiments and numerical analysis. The plastic deformation capacity of these beams are evaluated by the difference of their material properties and width-thickness ratio of these plate elements. And the plastic deformation capacity of high strength steel beams are compared with one of the ordinary steel.
