High energy electron beams, because of their sharp dose fall-off at the perlp hery and rapid dose build up for tumor have come to be used frequently for tumor radio-therapy, however, also have a lot of problems in clinical application because of various conversion factors and compliation of physical reactions. We have experimentally studied the dose distribution of scatting materials and high energies from the linear accelerator LMR-13, installed in Yonsei Cancer Center. 1. The electron energies are measured precisely with energy spectrometer consisted of magnetic analyzer and tele-control detector, and the practical electron energies are calculated under 5% errors by maximum range of high energy electron beam in the water, and energy of electron is decreased as about 2MeV by penetrating of 1cm thickness of water. 2. The electron beams, using the scatterers and cones with various materials, ie., gold, tin, copper, lead, lucite, acryl, aluminium foils, could be adquately distri uted in tumor and minimizing the induce x_ray I normal tissue. 3. The therapeutic capacity with limited electron energy could be extended further using by optimum scatterers, cones and energy absorbers.