This paper presented a proposal for a new reinforcing system to improve punching shear resistance of composite column-flat slab connections. Results on thirteen specimens tested under vertical static loading are presented. The influence of the slab thickness and the steel system characteristics were considered. In addition, a non-linear finite elements analysis was carried out using ANSYS code. The key parameters namely the concrete compressive strength, steel reinforcement yield strength, column rectangularity ratio, slab rectangularity ratio, tension steel reinforcement ratio, and steel system characteristics were investigated through a parametric study adopting NLFEA. Test results revealed enhancement in the failure load ranging between 2.53% and 33.5% for the specimens provided with the suggested reinforcing system. In general, the punching shear resistance increased by increasing the reinforcing angles length, while changing the steel section shape inside the composite column had no significant effect on the failure load.