Abstract: In order to investigate the vertical shear bearing capacity of a composite beam with a web opening, five composite beams with web openings and a contrasting composite beam under a concentrated load were tested.The six beams were all full-interraction, and the major parameters included thickness and reinforcement ratio of a concrete slab. Directional monotonic loads were applied and test measurement included a vertical load, deflection, slip and strain of cross-sections of a composite beam, etc. The test results show that the stiffness and ultimate capacity decreases notably with the area reduction of the composite beam web. According to the longitudinal strain distribution along section height at the hole region, the plane hypothesis is not satisfied any more. The ultimate load carrying capacity and deformability of a composite beam with a web opening can be effectively enhanced by increasing the thickness and reinforcement ratio of a concrete slab. The concrete slab at the top of the hole bears most of the total shear force of a cross-section, which makes a greater contribution to the shear bearing capacity. This study provides an experimental basis for the application of composite beams with web openings.