Seismic design of buildings has been well developed and is being continually updated and improved. But nonstructural elements in buildings are rarely designed with the same care or under the same degree of scrutiny as buildings. As a result, buildings that remain structurally sound after a strong earthquake often are rendered unserviceable due to damage to their nonstructural elements, such as access floors, telecommunication equipment and others. This damage has caused interruption of operations and large economic losses in the past. The objective of this study is to evaluate the seismic safety of computers and sensitive equipment of an existing internet data center(IDC) building. The approach to this study was to perform analytical and simulation studies of the seismic vulnerability of equipment in buildings. As a consequence, the floor acceleration are amplified and the secondary effects further deteriorate the earthquake resistant capability of the access floor systems.