Abstract: Taking a practical high framed-tower with large long-diameter ratio for petro-chemical project as the object， the structure response of high framed-tower with gap limiting support under the seismic effect was analyzed with timehistory analysis，whose results were compared with a combined structure model． The analysis indicated that the change in horizontal displacement of the high framed-tower with gap limiting support had the characteristics of increase in time step，max top displacement of tower was 50% greater than that of the high framed-tower of the combined structure model; and the seismic effect would also cause oscillation contact between tower and frame，and the pressure generated by the contact acted on the tower shell in mode of pulse force，which caused stress concentration in local area and a rapid change in stress amplitude． The type of structure model had low influence on stability of the stress variation of tower bottom and reaction variation of frame support． Based on the analysis，it could also be considered that the high framed-tower with gap limiting support was a multi-system structure． There would be some risks if taking single combined structure model to perform engineering design for a high framed-tower． Under the case of no determined stipulation of current design codes，use of time history analysis method was suggested for seismic effect．