Abstract: To investigate the influence of beam and column’s restraint and reinforcement arrangement on the residual capacity of fire-damaged concrete beam-slab assemblies, the residual strength test of 6 specimens were conducted, including four fire-damaged specimens and two reference specimens. The mechanical properties of these specimens were investigated, including the cracking pattern, the concrete and reinforcement strains, the load–deflection curves, the limit loads and failure modes. The comparison between the present experimental results and other tests was also conducted. Based on the ellipse method, the plane equation, the displacement ratio and the concept of four-equal-point were proposed to the calculations of modified yield-line load and limit load of the beam-slab assemblies, and the effects of vertical deflection, column’s restraint and temperature were considered. In addition, the present theoretical results were compared with those obtained by other methods. Results show that compared with the case without the vertical restraint of beams and columns, the ultimate bearing capacity of the floor with vertical restraint is increased by about 10%-30%. Meanwhile, the comparison with the case without the top continuous rebar shows that the existing of continuous rebar leads to less cracks, particularly in the top surface region, and it can increase the bearing capacity of the floor by 10%-20%. Compared with the reference beam-slab assemblies, the fire-damaged beam-slab assemblies have large crack spacing and crack width, and exhibit local punching shear failure. Neglecting the interaction between the slab and the beam, the limit loads predicted by the conventional yield-line method and the membrane action method are relatively conservative, and the present results are relatively reasonable since the beam-column restraint and the beam’s displacement are considered in the method.