Migrations of seismic activity observed after large earthquakes which occurred in and near the Japanese Islands are investigated, A common feature of migrational phenomena in the six cases which are studied in this paper is that migration occurred along geological tectonic zones, Sometimes existence of active tectonic zone is reconfirmed by the appearance of migrational phenomena, Analogizing to plate boundary regions where seismic activity is known to migrate or diffuse along mechanically coupled plane, we can consider that inland active tectonic zones correspond to mechanically interacting boundaries of crustal blocks. It is likely that more than one type exist in miqrational phenomena. In the cases we investigated following characteristics are observed that velocity of migration is about several km/year, seismic gaps remain between focal regions of large earthquakes, and there are seismically active periods in each seismic belt. A possible mechanism of migration is successive break down of asperities in which tectonic stress concentrates by relative movement of crustal blocks.