A conductive composition is obtained by dispersing conductive particles in a curable polymer. At least 50% by weight of the entire conductive particles are those conductive particles coated with a metal on their outermost layer surface and having a specific gravity which differs within ±1.5 from the specific gravity of the curable polymer. The composition remains stable during storage, experiences a minimal change with time of curability, and cures into a conductive rubber which experiences a minimal change with time of volume resistivity.