Abstract: A novel and very effective method is proposed for the stabilization of a higher aliphatic compound having at least one double bond in a molecule such as the sex pheromone compounds of agricultural pest insects used for the elimination of the pest insect by the method of mating disruption. The method comprises admixing the sex pheromone compound with each a specified amount of (a) a specific phenolic compound, e.g., tert-butyl hydroquinone, di-tert-butyl hydroquinone, di-tert-amyl hydroquinone, di-tert-butyl p-cresol, methyl hydroquinone and p-methoxy phenol, as an antioxidant and (b) 2-(2'-hydroxy-3'-tert-butyl-5'-methyl phenyl)-5-chloro benzotriazole in combination.