This thesis presents the results of experimental, numerical and analytical studies to investigate two shear connection systems to provide punching shear resistance between flat slabs and steel tubes. Shear connector system 1 relies purely on welded shear studs around the steel tube section and shear connector system 2 incorporates welded shear studs, steel plate and bent-up rebars. The aim of this research is to develop a simple shear connection system that can allow two of the most popular structural systems, reinforced concrete flat slab and steel tubular column to achieve construction efficiency and to reduce construction cost. For each shear connection system, physical tests were carried out to provide experimental data to validate relevant ABAQUS numerical finite element simulation models. These tests were carried out in the University of Manchesterâs Structural Testing Laboratory. The validated numerical simulation models were used to perform extensive numerical parametric studies to investigate the effects of changing different design parameters of these two shear connection systems, so as to develop a thorough understanding of their punching shear behaviour and to provide comprehensive data for development of analytical methods for design. For shear connection system 1, the experimental and numerical studies have investigated the effects on punching shear behaviour and resistance of different design variables including concrete depth above the shear stud, concrete compressive strength, concrete tensile strength, shear stud dimensions (length and diameter), and reinforcement. The concrete capacity method (CCD) was modified to develop an accurate analytical method. However, this shear connection system is unlikely to be able to provide sufficient slab punching shear resistance for practical applications. For shear connection system 2, two full scale column-slab assemblies were carried out, one representing interior position column and one for corner position column. The numerical parametric study investigated the effects of different design parameters including flat slab depth, concrete grade, bent-up rebar design, shear stud dimensions (length and diameter) and steel tube size. An analytical design method was developed to calculate the capacities of shear studs, bent-up rebars and slab punching shear resistance as an enlarged column. Shear connection system 2 is simple to construct in practice. For this system, it is easy to prevent shear stud failure and bent-up rebar failure so that the system behaves as an enlarged column for calculating punching shear resistance of the slab. The punching shear resistance of the enlarged column can be calculated using the design method in EN 1992-1-1 (CEN, 2004a), and has been demonstrated to be sufficient for practical applications in flat slab construction.