This study focuses on the experimental evaluation of steel-concrete composite member seismic performance. Relationships between the members' seismic performance and structural parameters, such as the sectional steel strength ratios and bi-axial bending magnitudes were defined. Test results show that the strength deterioration rates increased when the members' steel strength ratios in the weak-axis were increased. The test results also suggested that steel strength ratios in the strong and weak sectional directions be adequately adjusted so that high member performance could be achieved. It is proposed in this study that the ratio between the strong and weak-axes steel strength ratios be set to approximately 2.2 to optimize the member's seismic performance. (C) 2008 Elsevier Ltd. All rights reserved.