Abstract: Two experiments were conducted to investigate the failure modes and ductility of composite beam-column joints in a middle-column-removal scenario. Two composite beam-column joints with open and closed type steel profiled decking were statically tested. The results indicate that the beam-to-column assemblies resist the upper load through flexural mechanism and compressive arching action at the beginning and gradually it transfers to catenary action in the later stage. The specimen with open type profiled decking could dissipate more energy via plastic hinge formed by upper flange buckling, but the composite property of the composite slab could not be guaranteed due to insufficient constraint between the decking and concrete. The specimen with closed type profiled decking experienced premature fracture at the lower flange, and the upper flange could not buckle because of the good constraint from decking. However, excellent composite property was ensured in the later stage of loading.