Abstract: Study on the effects of tube-diameters on T-shaped concrete-filled steel tube core column antiknock properties. The dynamic responses on the T-shaped concrete-filled steel tube core columns with different tube diameters under a blast load were simulated by the finite element analysis software ABAQUS. The differences of antiknock properties were compared between those of ordinary T-shaped reinforced concrete columns and those of T-shaped concrete-filled steel tube core columns. By changing the diameter of a steel tube, we attained the influence of different tube diameters on the antiknock property of T-shaped concrete-filled steel tube core columns. Finally, we draw a conclusion: the antiknock property of T-shaped concrete-filled steel tube core columns is better than that of common T shaped reinforced concrete columns. The antiknock property of T-shaped concrete-filled steel tube core column is strengthened with the increasing of a steel tube diameter.