Abstract: In this paper,the author advocates a new dynamical theory of the Earth,attempting to unify plate tectonics and plume theories.Although the new dynamical theory may be judged as based on two unusual hypotheses to be verified by further observations,it is still possible that a consistent model of how the planet works may have been unveiled.The new theory admits the Earth's inner core to be a ferromagnet.The ferromagnetism of inner core is supported by observed anisotropic property of inner core in transmitting seismic waves.Since the torque caused by the magnetic interaction between the Earth and Jovian planets only acts on the iron cole,the core behaves as a rotating engine,tending to change both the rate and axis of Earth's rotation,while the mantle is the resistant to any change of Earth's rotation due to its inertia.The interplay between the two leads to the formations of fluid outer core,basalt magmas,oceanic crust,and differential rotation between the inner core and mantle.Rock materials at the core, mantle boundary are ground into basalt magmas due to the differential rotation between the inner core and mantle.Mid-ocean ridge systems are interpreted as the huge dike systems rooted in some principal magma chambers in the core-mantle boundary layer.The new theory assumes that the driving force of global tectonic movement comes from the external space.Tectonic movements in both continental crust and oceanic crust are the phenomena of surface difusion,which are influenced by the Earth's background radiation and by the matter distribution in the Earth's crust.The anisotropy of background radiation in the polar directions determines the geometric pattems of mid-ocean ridge systems on the Earth's surface and global tectonic movement of the Earth's crust. The Earth currently sufers stronger radiation on to the South Pole than on to the North Pole.The blowing force caused by the anisotropic radiation in the polar directions drives the continents drifting toward the North Pole.The current anisotropy of background radiation in the polar directions moreover results in the pear-shaped Earth with the tensile deformation of Earth developed in the southern hemisphere and the compressive deformation of Earth developed in the northern hemisphere.The asymmetrical Earth deformation produces the present geometric patterns of mid-ocean ridge systems (as the dikes always take the orientation perpendicular to the minimum compressive stress)and determines the modes of sea-floor spreading.History of the Earth is featured by three stages:that without the oceanic crust(before 2.7 Ga),creation of the oceanic crust(2.7～2.25 Ga)and growth of the continental crust(after 2.25 Ga).