Abstract: To understand their fire resistance and failure mode, an experimental study was performed on four full-scale cross steel beam-column T-stub joints by using a vertical furnace. The load was kept constant during the fire. The key parameters investigated include the thickness of the T-stub, the diameter of the bolts, and the floor on beams. The temperature distribution and the deformation of the T-stub joints in fire were measured through the test. The deformation-curves of the beams are then discussed. The results show that the failure modes of the T-stub joints in fire depend on the relative bearing capacity between the T-stub and bolts, and the damage occurs in the weaker of the two. The floor can greatly enhance the fire-resistance of the T-stub joints, while the thickness of the T-stub and the diameter of the bolts have little influence on the fire performance of the joints. The fire-resistance and stiffness of T-stub joints decrease sharply after 500℃~650℃.