Abstract: The safe operation for the tower structure of ship lift acting by the earthquakes load on Three Gorges Project is investigated by an elasticity similar model scaling 1: 100 in this paper. By using an time-domain method of experimental modal analysis technique, the modal parameters of the tower structure are identificated. The amplitudes of the tower structure are preliminary estimated by a classical response spectra of resolved mode shape. The time-histories for amplitude of the typical measuring points and for relative amplitude of the measuring points of the tower top, and its statistical values are estimated by computerized simulation using an input of earthquake ground motion. After the sensitivity analysis of structural dynamic characteristics the optimum design of tower structure is proposed. Calculated results are proved that the anti-seismic capability of the tower structure for the modified design is better than original.