Abstract: This paper investigates the seismic behavior of an improved square steel hollow column to steel beam joint. Three cruciform specimens are subjected to low cyclic loading to investigate the influence of the T-shape connector and beam depth ratio on the shear strength and deformation capacity of the panel zone. For comparison with the experimental data, numerical analysis is carried out by finite element software MSC. Marc 2012. The finite element model can simulate the performance of the cruciform specimens with high accuracy. The results of the experiment and the finite element analysis indicate that the stress concentration of the improved joint occurs in the welds between the T-shape connector and Beam 2. The deformation contribution of the components is similar to each other for all specimens. The shear strength and accumulated energy dissipation of the improved joints are increased by 20% and 200%, respectively. A design method for the T-shape connector is proposed, which provides the design basis for engineering practice in the future.