Hybrid structures with steel plates and concrete have considerable potential for use in offshore facilities. By replacing reinforcing bars with the steel plates, the structural performance of the member can be almost unchanged and the cost of form work and the period of construction can be considerably saved.
　For the hybrid structures, adequate shear reinforcement is required because the shear connectors will initiate cracks. Flexural and shear resisting mechanisms have to be fully investigated and new methods of shear reinforcement have to be developed.
　This paper presents the results of flexural and shear loading tests on hybrid beams with newly proposed shear reinforcements. Furthermore, load carrying mechanisms against shear and flexural forces are investigated and their design methods are established on the basis of the test results.