Push-out loading tests were carried out to investigate the ultimate strength and deformation of shear connectors in steel concrete composite members. Each push-out specimen consisted of a wide flange steel beam, two rectangular concrete blocks, and two shear connectors. The shear connectors were attached to the beam by the continuous fillet weld.
　Angles, channels and Tshapes of commercial standard sizes were used as the shear connectors. In this test, the following four parameters were taken into account; ⅰ)shapes and sizes of shear connectors; ⅱ) directions of flange of angles; ⅲ)strength of concrete; and ⅳ) directions of concrete placement. Fifty-eight unique specimens were tested.
　Shapes and directions of shear connectors and concrete strength had greatly effects on the mode of failure of push-out specimens. The modes of failure of the specimens were classified into three categories : tensile fracture of the shear connector, crushing of concrete, and shear failure of concrete.
　The shear connectors of the ratio of their thiskness and web length was smaller than 10 led to large load-carrying capacity provided that the same weight of connectors were used. An empirical equation regarding the load-carrying capacity of shear connectors of angles, T shapes, and channels was obtained, which was the function of their thickness and length and concrete strength.