Electron beams, because of their sharp dose fall-off and rapid dose build up, have come to be used frequently for radiation therapy, however, have defects that their constriction of isodose curve at depth. These defects of electron beams would be some compensated by electron cones which were made of the most adequate scattering materials according to field sizes and electron energy. We observed the scattering distribution and radiation absorption of various materials; ie., lead, brass, acryl, steel, aluminium, copper etc, for 8, 10, 12 MeV electron beams. By these data, we designed and made of election cones which would be delivered the most useful dose distribution in tissue according to electron energy and field sizes. The features of new developmental electron cone would be summarized as follows, 1) Shielding plates, consisted of 1cm Al, 5mm Pb, 5mm Al and 1cm Acryl, absorbed of 12 MeV electron beam completly and were very effective to minimized of bremsstrahlung. 2) Electi n cones which their walls were composed of 1g/$ extrm{cm}^2$ thickness of transparent materials were convenient to set up and collimate on tumor fields. 3) In small field sizes (10~50$ extrm{cm}^2$), they have favourable dose distribution to use combinded wall materials as acryl and Al plates. 4) In medium field sizes (50~200$ extrm{cm}^2$), the dose distribution of electron cones, nothing to do with their composed materials, were relativly satisfactory as 2~5% flatness ratio. 5) Designed the cones of 200$ extrm{cm}^2$ fields above, it has better dose disibution to make with brass then acryl plates. 6) It was no good to use the lead plate with relatively large bremsstrahlung and materials contained elements to be radioactivated. 7) For increasing of surface dose without energy loss, the 40~60mesh wire netting attached to cone edge are widly used. 8) The materials used in electron cones such as lead, acryl, aluminium, brass etc., were easy to acquire with reasonable price and tractable.