It is generally recognized that seismic isolated structures have an excellent seismic performance, particularly after the Hyogoken Nanbu Earthquake in 1995. In practical structural design using the Nortification-No.2009 of Ministory of Land, Infrastructure and Transport in which are applied to the seismic isolated structures, the response deformation of each devices, i.e. isolator and damper, are to be within the allowable design deformation, and the tensile stress is not permitted in the isolators considering the vertical seismic coefficient ±0.3, furthermore the eccentricity of the isolated story is to be less than 3%. This paper describes the vertical seismic coefficient by the dynamic response analysis based on the base-fixed model and dynamic soil-structure interaction model.