In this paper we review present theories relating to the formation of the earth’s radiation belts and consider prospects for future development of these theories. The first part is devoted to the discussion of the possibility of particle injection into the zone of trapped radiation when the drift orbits of particles are perturbed during geomagnetic storms. In the second part we show that the experimental data on particle diffusion in the belts are generally in agreement with the concept of sudden impulses. The third is an analysis of the problem of proton and electron leakage due to ionization deceleration and cyclotron instabilit