The purpose of this study is to verify the design method on the hybrid caisson. This paper presents the results of flexural and shear loading tests on hybrid beams which are designed as the vertical or horizontal section of a caisson wall.
　The experimental results show that the design method of the hybrid slab of bridges is applicable to the hybrid caisson, and that the formula in concrete standard of JSCE is applicable to the cstimation of crack width of hybrid caisson.