Since 1962, strong-motion earthquakes and earthquake responses of structures have been observed in the major ports in Japan. The strong-motion earthquake observation network in port areas in Japan consists of 91 strong-motion accelerographs installed at 60 ports as of March 1999. 65 accelerographs out of 91 are installed at ground surface, 22 accelerographs are in ground by using bore-hole and the rest 4 are on structures such as quay walls.
　This report presents site characteristics and status of these recording stations. Though this report is the sixth issue in this series, this report have been compiled as the summary of site data of strong-motion observation in this two decades. The report consists of the history and present state of the network, and site characteristics data of strong-motion observation station.