We have identified Late Jurassic to Early Cretaceous magnetic anomaly lineations (M0 to M35 of the Japanese and Hawaiian lineation sets) and fracture zones in the northwestern Pacific more comprehensively than previous investigators. We fixed 3500 positions of magnetic anomalies identified from magnetic data collected along cruise tracks as well as 151 positions of fracture zones from bathymetric and seismic profiles. The resultant isochron map revealed the evolution of the triple junction of the Pacific, Izanagi, and Farallon plates and the intimate relationship between the triple junction and the origin of the Shatsky Rise. The triple junction stagnated on a hotspot (the Shatsky hotspot) from chron M21 (149.5 Ma) to chron M4 (126 Ma). The Shatsky Rise is a trace of the hotspot on the Pacific plate. A sudden appearance of the Shatsky hotspot between chrons M21 and M20 caused a regional reorganization of the Pacific-Izanagi-Parallon plate boundaries. ¿ American Geophysical Union 1989