In this paper, the synchronous activity natures and the tectonic charac-teristics of the deep focus and shallow focus earthquakes in the continent of northeast China have been studied. It is considered that the action of the Northwest Pacific Plate is the dynamics of synch-ronous activity of deep focus and shallow focus earthquakes. The Northwest Pacific Lithosphere Plate underthrusts in the upper mantle of Huichun area with the depth of 590km. It results in the activities of deep earthquakes. Meanwhile, it affects the shallow earthquake activities in Tanlu Rift Zone and the fault zone in the margin of Songliao Basin and its adjacent area directly.