PURPOSE: To provide the titled resin compsn., by blending specified metallic compds. and resin with a polyolefin resin and irradiating the mixture with electron beams to crosslink the resin.

CONSTITUTION: At least 50pts.wt. mixture consisting of a hydrated metal oxide such as aluminum hydroxide or magnesium hydroxide and zinc borate (the proportion of the hydrated metal oxide in the mixture being 25W75wt%) and at least 10pts.wt. fluororesin powder such as tetrafluoroethylene resin having a particle size of 25μ or below are blended with 100pts.wt. polyolefin resin such as polyethylene or an ethylene/vinyl acetate copolymer. The resulting compsn. is irradiated with electron beams to crosslink it.