In long-period ground motions, high-rise buildings are subjected to large cumulative deformations as well as large story drifts. Retrofitting with dampers may be one of the most effective solutions reduce such seismic responses. This study examines the influences of steel dampers partially installed into the lower part of high-rise buildings. A series of dynamic response analyses are conducted for typical steel high-rise buildings. A long-period ground motion is adopted whose energy spectrum has a peak amplitude at three seconds, and twenty-one story buildings and thirty-five story buildings are substituted by frame models. The results show that the total energy absorption of the dampers installed into forty-percent stories can be equivalent to that of the dampers installed into the whole stories. On the other hand, the maximum drift of the story located right on the lower part having dampers would become 1.4 times larger than those of the lower part.