On December 8, 2025, an earthquake of magnitude 7.6 occurred in the eastern sea area of ??Honshu, Japan (OFF-AOMORI). The ground motion data monitored by the Japan Trench earthquake and tsunami observation network S-net and the land area networks K-NET and KiK-net were processed, and a total of 68 sets of offshore ground motion records and 417 sets of onshore ground motion records were selected. The differences between the offshore and onshore ground motion were explored from the ground-motion parameters such as peak ground acceleration (PGA), acceleration response spectrum (Sa), and significant duration of the OFF-AOMORI earthquake, and the applicability of different subduction interface ground-motion prediction model equations (GMPE) to the offshore earthquake was tested. The results showed that: (1) The PGA, acceleration response spectrum and duration of the offshore ground motion of this earthquake were generally greater than those of the onshore ground motion; the vertical PGA of the offshore ground motion was significantly smaller than that of the horizontal direction. (2) Due to the differences in the propagation path and site conditions of the ground motion models, the distribution of horizontal PGA and response spectrum residuals showed a significant shift within the event. (3) There are differences in the seismic motion characteristics between buried and unburied stations: the horizontal differences may be related to the effects of seafloor topography, while the vertical differences may be affected by the changes in station-seabed coupling conditions caused by the deployment method. The analysis results of the ground-motion parameter characteristics and attenuation of the OFF-AOMORI earthquake in this study provide a reference for the establishment and improvement of offshore interface ground motion prediction models in the subduction zone.