This paper presents seismic response analysis of high-rise buildings subjected to long-period strong ground motions predicted in Kansai area during large earthquakes along the Nankai Trough. Two steel building models, 75m and 150m in height and designed according to common practice in the 1970s early developmental stage in Japan, are prepared to simulate seismic response under predicted ground motions obtained from four different estimation methods and source models. Maximum response of models are investigated with respect to predicted sites, estimation methods, earthquake source, variation of magnitude of earthquakes and dynamic characteristics of structures. Demand of plastic deformation for steel moment frames and moment connections during earthquakes are also revealed.