It has been recognized by a number of investigators that the rocking excitation during strong earthquake ground motion may contribute significantly to the overall response of structures, Studies by Bielak, 1978; Yim et al., 1980; Ishiyama, 1982; Psycharis and Jennings, 1983; Koh and Spanos, 1984; Kashefi and Trifunac, 1986 and Gupta and Trifunac, 1987 have indicated the importance of studying the rocking contribution to the total response of structures. At present there are no recorded strong motion rocking accelerograms. However. by using the theory of elastic wave propagation in layered medium it can be shown that the rocking accelerations are related to the translational accelerations of ground motion (Trifunac, 1982). Therefore, it is possible to generate the rocking accelerograms from the recorded components of translational acceleration (Lee and Trifunac, 1987)