The report presents the results of strong-motion earthquake observation in Japanese ports in 1975; all the accelerograms obtained in the network are listed with thein maximum component accelerations, being classified in accordance with the earthquakes.
　On accelerograms with maximum acclerations exceeding 20 gals the wave forms are shown; on accelerograms exceeding 50 gals and recorded on ground, degitized records, response spectra and Fourier spectra as well as wave forms are presented.
　This is the eleventh publication in the series. The observation network consists of 69 strong-motion accelerographs (SMAC-B2 and ERS acceierographs) and 1058 accelerograms have been obtained in the network as of December 1975.