With the increase of the height, the lateral stiffness of high-rise buildings decreased. The high and flexible structures would have large movement when they are suffered lateral forces arising from earthquakes and winds. Compared with the ordinary high-rise buildings, the dynamic characteristics of the connected tall building will be changed by the connection; its seismic response and background of excitation are more complicated. Various finite element models with different connection location are established in order to find out the change of dynamic characteristics caused by the connection. According to modal analysis, the natural periods and mode shapes of different models are obtained. By utilizing the time history analysis method, El Centro earthquake wave was inputted, the seismic responses are obtained. The difference of results and summarized variation of dynamic characteristics with connection factors are analyzed. The results show that structural natural period and mode shape will be changed when the connection position changing. Under the seismic excitation, the change of location has little effect on the displacement time history and the maximum displacement, but the influences to the acceleration time history and the maximum acceleration value are obvious.