Based on the records of strong-motion accelerographs during the Higashi-Matsuyama earthquake of 1968, how the dynamic characteristics of earthquake inputs to building structures differ according to different soil condition and different foundations are discussed, and the importance of the soil-foundation-structure interaction problem is emphasized.

* Manuscript received on January 23, 1968.
** Research Member of Building Research Institute, Ministry of Construction
*** Visiting Member of Building Research Institute, Ministry of Construction
(from Kajima Institute of Construction Technology)