PURPOSE: To provide a crosslinkable polyolefin compsn. which does not discolor a conductor when said compsn. is coated on the surface of said conductor and crosslinked, by blending a crosslinking-agent having tert-butyl groups, an antioxidant and a specified conductor discoloration-inhibiting agent.

CONSTITUTION: A crosslinking agnet having tert-butyl groups such as di-tert- butyl peroxide, an antioxidant having a tert-butyl group such as 4,4'-thiobis(6-t- butyl-3-methylphenol) and a conductor discoloration-inhibiting agent, e.g., an epoxy stabilizer such as diglycidyl ether derived from 2,2-bis(4-hydroxy-phenyl) propane and (2-methyl)epichlorohydrin, are blended with a polyolefin as a base resin such as polyethylene or an ethylene/vinyl acetate copolymer.