A spatial 3-Dimensional distribution of the electron component of the Earth's radiation belts obtained by numerical solution of the diffusive transport equation taking into account both Coulomb collisional interaction losses and synchrotronic radiation (SR) energy degradation is presented. For boundary conditions, high energy, 3--16 MeV, electron fluxes observed at geosynchronous orbit by the GOES-7 spacecraft were used. Comparisons of electron distributions with and without the inclusion of SR losses show that energy losses from relativistic electrons substantially influence energy and space distributions of not only relativistic electron fluxes, but also of hundred keV electron fluxes. ¿ 1998 American Geophysical Union