Abstract: Based on the concept of the change in co-seismic Coulomb stress resulting from the interaction of faults, the earthquake trigging and delaying effects of fault interaction are proposed in this paper. The influences of fault interaction on the activity and seismic potential of faults as well as the spatial distributed image of aftershocks are analyzed. From the viewpoint of fault interaction, the possible physical mechanism of the quasi-periodically clustering recurrence behavior of continental strong earthquakes is discussed. It is concluded that the fault interaction is very significant for both seismology and geology. In the quantitative assessment of fault activity and seismic potential and in the prediction of aftershock distribution, the influence of fault interaction should not be ignored.