Abstract: The reduction of earthquake disasters includes the assessment of seismic hazard, estimation of seismic risk, and management of earthquake disasters. Physics plays an important role in the research and applications related to seismic hazard reduction. We discuss the important physical issues related to seismic disaster reduction, including the strong ground motion and engineering impact of earthquakes, complex systems and social impact, the change of stress state within the Earth, and earthquake prediction. These problems are of great concern to seismologists, engineering seismologists and earthquake engineers, and are closely related to the frontiers of modern physics.