Seismic damages reported during past major earthquakes have clearly demonstrated the critical role of nonstructural elements and the importance of seismic design of nonstructural elements. Suspended ceiling systems are the most frequently reported earthquake-vulnerable nonstructural elements. Despite their importance, suspended ceiling systems are still designed empirically rather than by a well-established engineering procedure because of their complex construction details and behavior. In this study, in order to evaluate the ceiling performance more realistically, dynamic tests of large-size suspended ceiling systems (13m x 5m) comparable to actual constructed size were conducted using an array of two shake tables. Including additional four smaller specimens (3.9m x 3.9m), a total of five ceiling specimens were constructed following a conventional non-seismic practice. Based on test results, overall seismic performances were evaluated and some of the key engineering parameters including the acceleration amplification factor, damping ratio and natural frequency were identified. Also, a deformation model to predict the natural frequency of suspended ceiling systems was suggested.