a method for preparing a magnetic recording medium comprising a non - magnetic support having coated thereon a magnetic layer containing plate - shaped ferromagnetic fine particles oriented perpendicular to a plane of the surface of the support , the process comprising the steps of : coating the non - magnetic support with a coating composition wherein ferromagnetic fine particles are dispersed in a solution comprised of a compound polymerizable by radiation with electron beams and a solvent , said particles being plate - shaped and having an axis of easy magnetization perpendicular to a plane of the plate - shaped particles ; orienting the ferromagnetic fine particles perpendicular to the surface of support while the coating composition is undried ; radiating the composition with electron beams ; and drying the composition by removing the solvent .