Three damaging inland earthquakes have occurred in the northern Miyagi Prefecture of the Tohoku District in Japan since 1900. Magnitudes M of the 1962 and the 2003 events were assigned to be 6.5 and 6.4, respectively, from local seismic records observed by the Japan Meteorological Agency (JMA). That of the 1900 event was 7.0, which was determined mainly from the seismic intensity data, while the rank of damage was very lower than other M=7 class inland shallow earthquakes in Japan. In the present study, damage rate data, seismic intensity data, and old seismograms were re-examined to evaluate the magnitude and the location of the focal region of the 1900 event. Re-evaluated magnitude of this event is almost the same as those of the 1962 and 2003 events. The seismic gap between the 1962 and 2003 events is filled with the focal region of the 1900 event obtained. The possibility of a big shallow earthquake occurrence must be very low in near future in the seismic zone of the northern Miyagi Prefecture.