This paper discusses the robust stability against spillover for various reduced-order control systems of an active dynamic vibration absorber for high-rise buildings. Four methods are investigated ; a LQ control using a reduced-order model, a spillover-considered suboptimal control, a spillover-considered suboptimal control using a low-pass filter, and an H-infinity control using a reduced-order model. In numerical calculations, it was shown that the spillover-considered suboptimal control using a low-pass filter can achieve higher performance than the H-infinity control under the condition of the limited order of the filter.