Because of high bearing capacity, the section of concrete-filled square steel tubular column is always smaller than that of concrete column under the same axial pressure. Therefore, the lateral stiffness of frame structure is tiny and should be improved by inclined supporter. For the sake of realizing the dynamic characteristics and seismic response of concrete-filled square steel tubular frame structure, two frame models composed of concrete-filled square steel tubular columns and steel beams with a scale of 1:5, which have single span, two-bay and five-story had been tested on modality and vibration table based on the current structure design codes. Inclined supporters were designed in one of these two models. Dynamic characteristic parameters (including frequency, vibration mode and damping ratio) and seismic responses such as acceleration, displacement and strain under different earthquake waves (El-Centro wave, Tianjin wave (N-S) and Wuhan artificial wave) of the frame models were obtained. In order to find out the varieties of the structure with inclined supporters, the experimental result of frame model with inclined supporters and that without inclined supporters were compared. The compared results shows: frequency and damping ratio of the frame model with inclined supporters are a litter higher than without that, but there is obvious difference in the first three frequencies of two models; Under the same earthquake waves, acceleration response trend is contiguous, the change of response value is gentle when using the supporters and it is sharper when without supporters; Strain amplitude of plinth is decrease greatly in the frame modal with supporters; the top floor displacement is larger in the model without supporters. Correspondingly the top floor displacement is smaller in the frame model with supporters. Then the-conclusions could be obtained by these results above: dynamic characteristic of concrete-filled square steel tubular frame structure can be measured by means of single-point input/output (SISO); under the intensity of 8 degree earthquake, the maximum displacement of the frame without inclined supporters is l8mm under three kinds of earthquake waves and dynamic magnification factor is 3.0. Overall deformation of the structure belongs to the type of bending; when using the supporters in the frame, the body stiffness increases, and seismic performance is better than that without inclined supporters.
