Abstract: In this research, the spatial and temporal evolution properties of the external radiation belt particles during geomagnetic disturbances have been investigated by using a three dimensional relativistic electromagnetic particle code. The calculation shows that, the injected energetic protons and electrons perform bounce movements along geomagnetic field lines and can expand into the high latitude region. On the other hand, the injected protons and electrons also experience clockwise and anticlockwise magnetic drift movements, the larger the energy of the particles is, the faster the drift velocity will be. Multiple injections will cause a remarforble increase o f the flux of the external radiation belt particles.