ABSTRACT: Records of excess pore water pressure changes as well as ground accelerations were obtained at Nakashimo, located near the mouth of the Naruse River, Miyagi Prefecture, during the earthquakes on 26 July 2003. Comparisons of records of two arrays at the site provide a unique opportunity to study the effectiveness of densification of sandy soil by the Sand Compaction Pile (SCP) method as liquefaction remediation. In the main shock, the peak ground acceleration was about 400 gal and the excess pore water pressure increased both in the improved and unimproved ground. The maximum excess pore water pressure ratio in the former was less than 0.4 while it was around 0.8 in the latter. These records suggest that marked increase of liquefaction resistance of soil can be expected for the densified ground with the low replacement ratio SCPs, even if the increase of SPT N -value by piling is insignificant.